RAD6-UBR2 ubiquitin ligase complex

A ubiquitin ligase complex consisting of RAD6 and UBR2 components. It may act in a quality control pathway for proteins synthesized on cytosolic ribosomes. The UBR2 component lacks sequence motifs required for N-end rule degradation.


Dcp1-Dcp2 complex

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A protein complex consisting of a Dcp1 regulatory subunit and a Dcp2 catalytic subunit that has mRNA cap binding activity and is involved in decapping of nuclear-transcribed mRNA.


COPII vesicles tethering complex

A protein complex that resides in the cis-golgi membrane and plays a role in the tethering of COPII vesicles, through an interaction with vesicle tethering proteins (p115 in H. Sapiens and Uso1 S. cerevisiae), granting the cis-Golgi and endoplasmic reticulum to Golgi vesicle-mediated transport. It is composed by GRASP65 and GM130 protein in H. sapiens and by Bug1 and Grh1 proteins in S. cerevisiae.


banded collagen fibril

A supramolecular assembly of fibrillar collagen complexes in the form of a long fiber (fibril) with transverse striations (bands).


oxidoreductase complex

Any protein complex that possesses oxidoreductase activity.


integrin alpha7-beta1 complex

An integrin complex that comprises one alpha7 subunit and one beta1 subunit.


inhibin B complex

Heterodimeric hormone composed of an inhibin alpha subunit complexed with an inhibin beta-B subunit.


light-harvesting complex

A protein-pigment complex that may be closely or peripherally associated to photosynthetic reaction centers that participate in harvesting and transferring radiant energy to the reaction center.


extracellular exosome complex

A protein complex that is wholly or partially contained within the lumen or membrane of the extracellular vesicular exosome.


Las1 complex

A four subunit complex, that comprises all the necessary RNA processing enzymes (endonuclease, polynucleotide kinase, and exonuclease) to mediate 'cistronic rRNA transcript ITS2 (internal transcribed spacer) cleavage' (GO:0000448).


proteasome core complex

A multisubunit barrel shaped endoprotease complex, which is the core of the proteasome complex.


SBF transcription complex

A protein complex that binds to the Swi4/6 cell cycle box (SCB) promoter element, consensus sequence CRCGAAA, and activates transcription during the G1/S transition of the cell cycle. In Saccharomyces, the complex contains a heterodimer of the DNA binding protein Swi4p and the activator Swi6p, and is associated with additional proteins known as Whi5p and Msa1p.


Toll-like receptor 2-Toll-like receptor 6 protein complex

A heterodimeric protein complex containing Toll-like receptor 2 (TLR2) and Toll-like receptor 6 (TLR6).


HslUV protease complex

A protein complex that possesses ATP-dependent protease activity; consists of an ATPase large subunit with homology to other ClpX family ATPases and a peptidase small subunit related to the proteasomal beta-subunits of eukaryotes. In the E. coli complex, a double ring-shaped homohexamer of HslV is capped on each side by a ring-shaped HslU homohexamer.


VRK3/VHR/ERK complex

A ternary complex consisting of VRK3, VHR (Dusp3), and ERK1 (Mapk3) existing in neuronal cells, and is involved in regulation of the ERK signaling pathway.


mitochondrial proton-transporting ATP synthase complex, coupling factor F(o)

All non-F1 subunits of the mitochondrial hydrogen-transporting ATP synthase, including integral and peripheral mitochondrial inner membrane proteins.


SCF-Ufo1/Pof10 ubiquitin ligase complex

An SCF ubiquitin ligase complex in which the F-box protein is Ufo1 in S. cerevisiae (Pof10 in S. pombe).


core TFIIH complex portion of holo TFIIH complex

The core TFIIH complex when it is part of the general transcription factor TFIIH.


preribosome, large subunit precursor

A preribosomal complex consisting of 27SA, 27SB, and/or 7S pre-rRNA, 5S rRNA, ribosomal proteins including late-associating large subunit proteins, and associated proteins; a precursor of the eukaryotic cytoplasmic large ribosomal subunit.


signal recognition particle, chloroplast targeting

A complex consisting of a protein and RNA component which binds the signal sequence of some proteins and facilitates their export to the chloroplast.


RPAP3/R2TP/prefoldin-like complex

A protein complex first characterized in human and comprised of a R2TP module (R2TP complex), a prefoldin-like module (containing both prefoldin-like proteins and canonical prefoldins), WD40 repeat protein Monad/WDR92 and DNA-dependent RNA polymerase subunit RPB5. This complex might have chaperone activity.


messenger ribonucleoprotein complex

A ribonucleoprotein complex containing both protein and messenger RNA (mRNA) molecules.


transcription repressor complex

A protein complex that possesses activity that prevents or downregulates transcription.


CFTR-NHERF-ezrin complex

A protein complex that contains ezrin, Na+/H+ exchanger regulatory factor (NHERF, also called EBP50), and two copies of the cystic fibrosis transmembrane conductance regulator (CFTR). The CFTR molecules interact with NHERF via their cytoplasmic tail domains; the complex is thought to link the CFTR channel to the actin cytoskeleton and contribute to the regulation of channel activity.


outer dynein arm

Outer arm structure present on the outer doublet microtubules of ciliary and flagellar axonemes. Outer dynein arms contain 2-3 heavy chains, two or more intermediate chains and a cluster of 4-8 light chains. Inner and outer dynein arms have different functions in the generation of microtubule-based motility.


exon-exon junction subcomplex mago-y14

Component of the core exon-exon-junction complex (EJC). Fairly conserved in eukaryotes; in Drosophila, consists of the Mago and Y14 (tsunagi) gene products. Important for coupling nuclear and cytoplasmic events in gene expression. Inhibits the ATPase activity of eIF4AIII (Q9VHS8) to ensure a stable association of the EJC core with the mRNA.


Nkx-2.5 complex

A transcription factor complex formed by two or more subunits of Nkx-2.5. Nkx-2.5 is an evolutionary conserved transcription factor important for the specification and differentiation of cardiomyocytes during heart development. It is also required for spleen development. It binds DNA either as a monomer, or a homodimer, or a heterodimer complex to activate or inhibit expression of genes.


BRCA2-BRAF35 complex

A heterodimeric complex of BRCA2 and BRAF35 (BRCA2-associated factor 35). The BRCA2-BRAF35 complex is often associated with condensed chromatin during mitosis.


myosin VIII complex

A myosin complex containing a dimer of class VIII myosin heavy chains and associated light chains. Myosin VIII is predicted to be dimeric, and contain an unusual 100-190 residue N-terminal extension prior to their motor domains, 3-4 IQ motifs, a short region (~70 residues) of predicted alpha-helical coiled coil and a C-terminal domain.


A SNARE complex that contains synaptotagmin, synaptobrevin 2 (VAMP2), SNAP-25, syntaxin 1a, syntaxin1b, and Rab3a (or orthologs thereof).


shelterin complex

A nuclear telomere cap complex that is formed by the association of telomeric ssDNA- and dsDNA-binding proteins with telomeric DNA, and is involved in telomere protection and recruitment of telomerase. The complex is known to contain TERF1, TERF2, POT1, RAP1, TINF2 and ACD in mammalian cells, and Pot1, Tpz1, Rap1, Rif1, Rif2 and Taz1 in Saccharomyces. Taz1 and Rap1 (or their mammalian equivalents) form a dsDNA-binding subcomplex, Pot1 and Tpz1 form an ssDNA-binding subcomplex, and the two subcomplexes are bridged by Poz1, which acts as an effector molecule along with Ccq1.


RecQ family helicase-topoisomerase III complex

A complex containing a RecQ family helicase and a topoisomerase III homologue (a member of the topoisomerase type IA subfamily); may also include one or more additional proteins; conserved from E. coli to human.


replisome

A multi-component enzymatic machine at the replication fork which mediates DNA replication. Includes DNA primase, one or more DNA polymerases, DNA helicases, and other proteins.


interleukin-7 receptor complex

A protein complex that binds interleukin-7 (IL-7) and that consists of, at a minimum, an interleukin, an alpha and a gamma chain as well as optional additional kinase subunits. The alpha chain binds IL-7 with high affinity and subsequently binds the cytokine receptor common gamma chain that forms part of multiple interleukin receptors.


eukaryotic 48S preinitiation complex

The protein-ribosome-tRNA complex that has just recognized the start codon of a capped mRNA. It is composed of the small ribosomal subunit, eukaryote initiation factors (eIF) eIF3 complex, eIF1, eIF1A, eIF2-GDP, eIF4 complex and initiatior-methionine-tRNA. Recognition of the start codon triggers downstream steps in the pathway, including eIF1 dissociation; Pi release from eIF2; and conversion to the closed, scanning-arrested conformation of the PIC.


CARD8 inflammasome complex

An inflammasome complex that consists of CARD8 and CASP1.


XRCC2-RAD51D complex

A heterodimeric DNA recombinase mediator complex that contains the Rad51 paralogs RAD51D and XRCC2, or orthologs thereof; conserved from fission yeast to human but absent from budding yeast.


ubiquitin activating enzyme complex

A protein complex responsible for the catalysis of the reaction: E1 + ubiquitin + ATP--> E1-ubiquitin + AMP + PPi, where the E1-ubiquitin linkage is a thioester bond between the C-terminal glycine of Ub and a sulfhydryl side group of an E1 cysteine residue. This is the first step in a cascade of reactions in which ubiquitin is ultimately added to a protein substrate.


mature chylomicron

A chylomicron that contains apolipoprotein C2 (APOC2), a cofactor for lipoprotein lipase (LPL) activity, and has a mean diameter of 500 nm and density of 0.95g/ml. Mature chylomicron particles transport exogenous (dietary) lipids from the intestines to other body tissues, via the blood and lymph.


hyphal tip polarisome

Protein complex that has a role in determining cell polarity, found at the tip of a growing fungal hypha.


Tea1 cell-end complex

A high molecular weight complex characterized in S. pombe containing the cell-end anchoring protein Tea1. This complex is transported to the cell ends by microtubules and is involved in bipolar growth and the maintennce of normal cell polarity.


A protein complex capable of catalysing the hydrolysis of the terminal (1->2)-linked alpha-D-mannose residues in an oligo-mannose oligosaccharide.


pre-T cell receptor complex

A receptor complex found on immature T cells consisting of a T cell receptor beta chain and the pre-TCR-alpha chain, along with additional signaling components including CD3 family members and additional signaling proteins.


protease inhibitor complex

A heterodimeric protein complex that contains a protease inhibitor and a protease; formation of the complex inhibits protease activity.


FMN reductase complex

A protein complex capable of FMN reductase activity. Reduces FMN to FMNH2 in a NAD(P)H-dependent manner. In E.coli, consists of a SsuE dimer.


xylanosome

A multifunctional supermolecular complex, containing several proteins with hemicellulase activity. Functions to hydrolyze hemicellulose.


inward rectifying potassium channel

A protein complex that comprises four pore-forming (Kir6.x) and four regulatory sulphonylurea receptor (SURx) subunits and forms a transmembrane channel through which ions may pass. The opening and closing of the channel is regulated by ATP: binding of ATP to the Kir6.x subunit inhibits channel activity, whereas binding of Mg2+-complexed ATP or ADP to the SURx subunit stimulates channel activity.


Dxr protein complex

A protein complex that is involved in the MEP pathway of IPP biosynthesis. It catalyzes the NADP-dependent rearrangement and reduction of 1-deoxy-D-xylulose-5-phosphate (DXP) to 2-C-methyl-D-erythritol 4-phosphate (MEP).


laminin-7 complex

A laminin complex composed of alpha3, beta2 and gamma1 polypeptide chains.


A protein complex that consists of an alpha9-beta1 integrin complex bound to thrombospondin-1.


protein tyrosine phosphatase complex

A protein complex which is capable of protein tyrosine phosphatase activity.


PKM2 pyruvate kinase complex

A protein complex capable of pyruvate kinase activity. PKM2 only exists as homotetramer when bound to beta-d-fructofuranose 1,6-bisphosphate (CHEBI:28013).


COP9 signalosome

A protein complex that catalyzes the deneddylation of proteins, including the cullin component of SCF ubiquitin E3 ligase; deneddylation increases the activity of cullin family ubiquitin ligases. The signalosome is involved in many regulatory process, including some which control development, in many species; also regulates photomorphogenesis in plants; in many species its subunits are highly similar to those of the proteasome.


Gemin6-Gemin7-unrip complex

A protein complex that contains Gemin6, Gemin7, and unrip (STRAP), and can bind to snRNAs; may play a role in snRNP assembly.


glutamate decarboxylase complex

A protein complex which is capable of glutamate decarboxylase activity.


Hedgehog signaling complex

A multiprotein complex that binds microtubules in a Hedgehog-dependent manner, and is required for signal transduction by members of the Hedgehog family of proteins. The core components of the complex are the serine/threonine protein kinase Fused, the kinesin motor protein Costal2 (Cos2), and a zinc finger transcription factor (Gli family members in humans, and Cubitus interruptus (Ci) in Drosophila).


XY body

A structure found in a male mammalian spermatocyte containing an unpaired X chromosome that has become densely heterochromatic, silenced and localized at the nuclear periphery.


AIM2 inflammasome complex

An inflammasome complex that consists of AIM2, ASC, and caspase-1. AIM2 is a member of the HN-200 protein family that appears to be the sensor of cytosolic double-stranded DNA.


PCSK9-LDLR complex

A protein complex consisting of the serine protease PCSK9 (proprotein convertase subtilisin/kexin-9) and a low-density lipoprotein receptor (LDLR). Interaction typically occurs through the epidermal growth factor-like repeat A (EGF-A) domain of the LDLR, and complex formation promotes degradation of the LDLR through the endosome/lysosome pathway.


alpha7-beta1 integrin-nicotinamide riboside kinase complex

A protein complex that consists of an alpha7-beta1 integrin complex bound to nicotinamide riboside kinase 2 (also known as muscle integrin binding protein, MIBP).


NLRP1 inflammasome complex

An inflammasome complex that consists of two components, NLRP1 (NALP1) and caspase-1 or caspase-5. The exact mechanisms of NLRP1 activation remain obscure, but potassium ion efflux appears to be essential.


platelet SNARE complex

A SNARE complex that is capable of fusing intracellular vesicles to the plasma membrane of platelets for exocytosis of alpha-granules or dense granules. Contains isoforms of VAMP, SNAP and syntaxin proteins. Ternary SNARE complexes interact in a circular array to form ring complexes or channels around the membrane fusion. A common composition in human is VAMP-8, SNAP-23 and syntaxin-2 or -4.


A protein complex that contains the cell adhesion molecules protocadherin-alpha-v7 and protocadherin-gamma-b4, and is involved in the regulation of protein localization to the plasma membrane.


thiazole synthase complex

A protein complex which is capable of thiazole synthase activity.


nitrate reductase complex

An enzyme complex that catalyzes the formation of nitrate from nitrite with the concomitant reduction of an acceptor.


methylcrotonoyl-CoA carboxylase complex

A protein complex which is capable of methylcrotonoyl-CoA carboxylase activity.


CD19-Vav-PIK3R1 complex

A protein complex that contains the cell surface signaling molecule CD19, the Ras guanine nucleotide exchange factor Vav, and the regulatory subunit alpha of phosphatidylinositol 3-kinase (PI3K).


Bfa1-Bub2 complex

A protein complex that acts as a two-component GTPase-activating protein for Tem1 GTPase, thus regulating a signal transduction cascade, called the mitotic exit network (MEN), which is required for mitotic exit and cytokinesis. Bub2/Bfa1 keeps Tem1 inactive until the spindle is properly oriented, thus inhibiting MEN activation.


CAF-1 complex

A conserved heterotrimeric protein complex that promotes histone H3 and H4 deposition onto newly synthesized DNA during replication or DNA repair; specifically facilitates replication-dependent nucleosome assembly with the major histone H3 (H3.1). In many species the CAF-1 subunits are designated p150, p60, and p48.


Complex that catalyzes the synthesis of ADP-glucose and pyrophosphate from glucose-1-phosphate and ATP. In plants, the complex is a heterotetramer composed of two types of subunits (small and large). In bacteria, the enzyme complex is composed of four identical subunits.


telomere-telomerase complex

A complex of DNA and protein located at the end of a linear chromosome that enables replication of the telomeric repeat sequences at the end of a linear chromosome.


ATAC complex

A chromatin remodeling complex that regulates transcription via acetylation primarily of nucleosomal histones H3 and possibly H4. Shares the histone acetylation (HAT) module of GCN5/PCAF-ADA2-ADA3-SGF29 (or orthologs) with the related SAGA complex (GO:0000124). Contains HAT subunits GCN5 or PCAF in a mutually exclusive manner. In addition to the HAT module contains DR1/NC2B, KAT14, MBIP, WDR5, YEATS2 and ZZZ3 or orthologs. Also regulates the activity of non-histone targets and orchestrates mitotic progression by regulating Cyclin A degradation through acetylation.


low-density lipoprotein particle

A lipoprotein particle, rich in cholesterol esters and low in triglycerides that is typically composed of APOB100 and APOE and has a density of 1.02-1.06 g/ml and a diameter of between 20-25 nm. LDL particles are formed from VLDL particles (via IDL) by the loss of triglyceride and gain of cholesterol ester. They transport endogenous cholesterol (and to some extent triglycerides) from peripheral tissues back to the liver.


tenascin complex

A extracellular matrix complex involved in cell adhesion and cell migration. Typically homotrimeric or homohexameric. In mammals, four complexes exist: Tenascin-C, Tenascin-N (also known as Tenascin-W), Tenascin-X and Tenascin-R.


U12 snRNP

A ribonucleoprotein complex that contains small nuclear RNA U12, a heptameric ring of Sm proteins, as well as several proteins that are unique to the U12 snRNP, most of which remain associated with the U12 snRNA both while the U12 snRNP is free or assembled into a series of spliceosomal complexes.


Rvs161p-Rvs167p complex

A protein complex that is involved in endocytosis in the yeast S. cerevisiae.


oncostatin-M receptor complex

A heterodimeric receptor for the cytokine oncostatin-M (OSM). In humans the receptor complex is made up of the gene products gp130 and OSMR-beta.


RNA polymerase V transcription regulator complex

A transcription factor complex that acts at a regulatory region of a gene transcribed by RNA polymerase V.


protein C inhibitor-KLK3 complex

A heterodimeric protein complex that contains protein C inhibitor (SERPINA5) and prostate-specific antigen (KLK3); formation of the complex inhibits the serine protease activity of prostate-specific antigen.


molybdopterin cofactor (Moco) biosynthesis adenylyltransferase complex

A heterodimeric protein complex which adenylates two molecules of the sulfur carrier subunit of the molybdopterin (MPT) cofactor synthase using ATP as part of molybdopterin cofactor (Moco) biosynthesis. In E. coli the subunits are MoeB and MoaD; Moco biosynthesis and its constituent molecules are evolutionarily conserved.


alphaV-beta3 integrin-CD98 complex

A protein complex that consists of an alphaV-beta3 integrin complex bound to the cell surface antigen CD98.


tRNA (m1A) methyltransferase complex

A protein complex involved in the catalysis of the formation of the modified nucleotide 1-methyladenosine (m1A) in tRNA. In yeast, it is a heterotetramer of two subunits, Gcd10p and Gcd14p, while in bacteria and archaea it is a homotetramer.


A protein complex which is capable of glycerol-3-phosphate-transporting ATPase activity.


classical-complement-pathway C3/C5 convertase complex

A heterodimeric protein complex that catalyzes the cleavage of complement components C3 and C5, and acts in the classical pathway of complement activation; consists of one monomer of C2a and one monomer of C4b; C2a is the catalytic subunit, but cannot catalyze cleavage alone.


alphaIIb-beta3 integrin-fibronectin-tissue transglutaminase complex

A protein complex that consists of an alphaIIb-beta3 integrin complex bound to fibronectin and tissue transglutaminase.


MOZ/MORF histone acetyltransferase complex

A histone acetyltransferase complex that has histone H3 acetyltransferase and coactivator activities. Subunits of the human complex include MYST3/MOZ, MYST4/MORF, ING5, EAF6 and one of BRPF1, BRD1/BRPF2 and BRPF3.


heterotrimeric G-protein complex

Any of a family of heterotrimeric GTP-binding and hydrolyzing proteins; they belong to a superfamily of GTPases that includes monomeric proteins such as EF-Tu and RAS. Heterotrimeric G-proteins consist of three subunits; the alpha subunit contains the guanine nucleotide binding site and possesses GTPase activity; the beta and gamma subunits are tightly associated and function as a beta-gamma heterodimer; extrinsic plasma membrane proteins (cytoplasmic face) that function as a complex to transduce signals from G protein-coupled receptors to an effector protein.


SCF-YDR131C ubiquitin ligase complex

An SCF ubiquitin ligase complex in which the F-box protein is YDR131C in S. cerevisiae.


A protein complex which is capable of pyrroline-5-carboxylate reductase activity.


IRE1-RACK1-PP2A complex

A protein complex consisting of IRE1 (Inositol-requiring enzyme-1), RACK1 (Receptor of activated protein kinase C 1, GNB2L1) and PP2A (protein phosphatase 2A). RACK1 acts as an adaptor to bridge an interaction between IRE1 and PP2A.


A SNARE complex that contains endobrevin (VAMP8), synaptobrevin 2 (VAMP2), alpha-SNAP, NSF, and syntaxin 4 (or orthologs thereof).


nuclear cap binding complex

A conserved heterodimeric protein complex that binds to the 5' terminal cap structure m7G(5')ppp(5')N of nascent eukaryotic RNA polymerase II transcripts such as pre-mRNA and U snRNA. The consists of proteins known as CBP20 and CBP80, binds to cap structures in the nucleus, and is involved in pre-mRNA splicing, 3'-end formation, and RNA nuclear export.


RNA polymerase III transcription regulator complex

A transcription factor complex that acts at a regulatory region of a gene transcribed by RNA polymerase III.


proton-transporting ATP synthase complex, coupling factor F(o)

All non-F1 subunits of a hydrogen-transporting ATP synthase, including integral and peripheral membrane proteins.


laminin-3 complex

A laminin complex composed of alpha1, beta2 and gamma1 polypeptide chains.


SWI/SNF superfamily-type complex

A protein complex that contains an ortholog of the Saccharomyces ATPase Swi2/Snf2 as one of the catalytic subunit components (ATPase) and mediates assembly of nucleosomes, changes to the spacing or structure of nucleosomes, or some combination of those activities in a manner that requires ATP.


primary cell wall cellulose synthase complex

A large, multimeric protein complex which catalyzes the biosynthesis of cellulose for the plant primary cell wall. In Arabidopsis, contains the essential component proteins CESA1 and -3, and a CESA6-related protein.


FANCM-MHF complex

A protein complex contains the proteins FANCM and MHF, or their orthologs, plays an essential role in DNA remodeling, protects replication forks, and is conserved in eukaryotes.


nuclear pore cytoplasmic filaments

Filamentous extensions on cytoplasmic face of the nuclear pore complex (NPC). In S. cerevisiae, Nup159p, Nup82p, and Nup42p contribute to the cytoplasmic filaments. In vertebrates, Nup358 is a major component.


alphav-beta3 integrin-CD47 complex

A protein complex that consists of an alphav-beta3 integrin complex bound to CD47 (also known as IAP).


endoplasmic reticulum chaperone complex

A protein complex that is located in the endoplasmic reticulum and is composed of chaperone proteins, including BiP, GRP94; CaBP1, protein disulfide isomerase (PDI), ERdj3, cyclophilin B, ERp72, GRP170, UDP-glucosyltransferase, and SDF2-L1.


chylomicron remnant

A lipoprotein particle that is derived from a mature chylomicron particle by the removal of triglycerides from the chylomicron core by lipoprotein lipase and the subsequent loss of surface components. It characteristically contains apolipoprotein E (APOE) and is cleared from the blood by the liver.


plasma membrane succinate dehydrogenase complex (ubiquinone)

The enzyme, located in the plasma membrane, that catalyzes the oxidation of succinate and ubiquinone to fumarate and ubiquinol; involved in aerobic respiration, repressed in anaerobic respiration.


protein serine/threonine phosphatase complex

A complex, normally consisting of a catalytic and a regulatory subunit, which catalyzes the removal of a phosphate group from a serine or threonine residue of a protein.


TBK1-IKKE-DDX3 complex

A protein complex containing TBK1 (TANK-binding kinase 1), IKBKE (I-Kappa-B kinase epsilon/IKKE/IKK-epsilon) and the DEAD box family RNA helicase DDX3.


striated muscle myosin thick filament

Bipolar filaments formed of polymers of a muscle-specific myosin II isoform, found in the middle of sarcomeres in myofibrils.


Fc-gamma receptor I complex

A protein complex composed of an Fc-gamma RI alpha chain and an Fc-epsilon RI gamma chain dimer with or without additional signaling components. The complex functions primarily as an activating receptor for IgG.


caveolar macromolecular signaling complex

A complex composed of proteins required for beta adrenergic receptor activation of protein kinase A. It includes the Cav 12. subunit of L-type calcium channel, protein kinase A regulatory subunit 2(PKAR2), adenyl cyclase, beta-adrenergic receptor, G-alpha-S, protein phosphatase 2A (PP2A) and caveolin 3 (CAV3).


receptor complex

Any protein complex that undergoes combination with a hormone, neurotransmitter, drug or intracellular messenger to initiate a change in cell function.


small nuclear ribonucleoprotein complex

A ribonucleoprotein complex that contains at least one RNA of the small nuclear RNA (snRNA) class and as well as its associated proteins. These are typically named after the snRNA(s) they contain, e.g. U1 snRNP, U4/U6 snRNP, or 7SK snRNP. Many, of these complexes become part of the spliceosome involved in splicing of nuclear mRNAs. Others are involved in regulation of transcription elongation or 3'-end processing of replication-dependent histone pre-mRNAs.


endonuclease complex

A protein complex which is capable of endonuclease activity.


Cul3-RING ubiquitin ligase complex

A ubiquitin ligase complex in which a cullin from the Cul3 subfamily and a RING domain protein form the catalytic core; substrate specificity is conferred by a BTB-domain-containing protein.


basal tubulobulbar complex

Actin-based structures involved in establishing the blood-testis barrier of the Sertoli cell.


ASTRA complex

A protein complex that is part of the chromatin remodeling machinery; the acronym stands for ASsembly of Tel, Rvb and Atm-like kinase. In Saccharomyces cerevisiae this complex includes Rvb1p, Rvb2p, Tra1p, Tel2p, Asa1p, Ttilp and Tti2p.


left caudal flagellum

A cilium (also called flagellum) found in Giardia species (trophozoite stage). It is nucleated by the left caudal basal body, extending cytoplasmically and exiting at the posterior end of the cell body.


Myb complex

A multisubunit complex consisting of Myb and other proteins that regulates site specific DNA replication, gene amplification and transcriptional repression.


alpha DNA polymerase:primase complex

A complex of four polypeptides, comprising large and small DNA polymerase alpha subunits and two primase subunits, which are capable of catalyzing the synthesis of an RNA primer on the lagging strand of replicating DNA and the subsequent synthesis of a smal stretch of DNA. The smaller of the two primase subunits alone can catalyze oligoribonucleotide synthesis.


alphaV-beta3 integrin-LPP3 complex

A protein complex that consists of an alphaV-beta3 integrin complex bound to lipid phosphate phosphohydrolase-3.


fatty acid synthase complex

A multienzyme complex that catalyses the synthesis of fatty acids from acetyl CoA.


RES complex

A protein complex that is required for efficient splicing, and prevents leakage of unspliced pre-mRNAs from the nucleus (named for pre-mRNA REtention and Splicing). In Saccharomyces, the complex consists of Ist3p, Bud13p, and Pml1p.


RNA polymerase complex

Any complex that possesses RNA polymerase activity; generally comprises a catalytic subunit and one or more additional subunits.


TORC2 complex

A protein complex that contains at least TOR (target of rapamycin) and Rictor (rapamycin-insensitive companion of TOR), or orthologs of, in complex with other signaling components. Mediates the phosphorylation and activation of PKB (also called AKT). In Saccharomyces, the complex contains Avo1p, Avo2p, Tsc11p, Lst8p, Bit61p, Slm1p, Slm2p, and Tor2p.


Nem1-Spo7 phosphatase complex

A protein serine/threonine phosphatase complex that is involved in nuclear envelope organization, and contains proteins known in budding yeast as Nem1p and Spo7p.


plasma membrane respiratory chain complex IV

A part of the respiratory chain located in the plasma membrane, containing the 13 polypeptide subunits of cytochrome c oxidase, including cytochrome a and cytochrome a3. Catalyzes the oxidation of reduced cytochrome c by dioxygen (O2). Examples of this component are found in bacterial species.


mannan polymerase II complex

A complex with alpha-(1->6)-mannosyltransferase activity, located in the cis Golgi membrane; adds mannan to N-linked glycans on proteins as part of the elongation of alpha 1,6-linked Man backbone. In S. cerevisiae, contains Mnn9p, Anp1p, Mnn10p, Mnn11p, and Hoc1p.


chaperone-mediated autophagy translocation complex

A lysosomal membrane protein complex that enables the translocation of a target protein across the lysosomal membrane as part of chaperone-mediated autophagy.


apolipoprotein B mRNA editing enzyme complex

Protein complex that mediates editing of the mRNA encoding apolipoprotein B; catalyzes the deamination of C to U (residue 6666 in the human mRNA). Contains a catalytic subunit, APOBEC-1, and other proteins (e.g. human ASP; rat ASP and KSRP).


Snt2C complex

A histone deacetylase complex that is part of the chromatin remodeling machinery. In Saccharomyces cerevisiae this complex contains Snt2p, Ecm5p and Rpd3p.


SIN/MEN signalling complex

A protein complex associated with the mitotic spindle pole body during interphase and mitosis and comprises of the proteins of the septation initiation signalling network (SIN) of fission yeast or mitotic exit network (MEN) of budding yeast, organized by two scaffold/adaptor proteins.


DnaB-DnaC complex

A protein complex containing homohexameric DNA helicase DnaB, and the DNA helicase loader DnaC. The helicase loader DnaC delivers DnaB to the chromosomal origin (oriC).


SHREC complex

A histone deacetylase complex that contains a core of four proteins -- Clr1, Clr2, Clr3, and Mit1 in fission yeast -- and localizes to all heterochromatic regions in the genome as well as some euchromatic sites. The complex is involved in regulating nucleosome positioning to assemble higher-order chromatin structures.


A protein complex that is formed by the association of a heterodimeric interleukin-12 receptor complex with an interleukin-12 heterodimer.


ATP-binding cassette (ABC) transporter complex, transmembrane substrate-binding subunit-containing

A complex for the transport of metabolites into the cell, consisting of 4 subunits: a transmembrane substrate-binding protein (known as the S component), and an energy-coupling module that comprises two ATP-binding proteins (known as the A and A' components) and a transmembrane protein (known as the T component). Transport of the substrate across the membrane is driven by the hydrolysis of ATP.


A protein complex that is formed by the association of a heterodimeric interleukin-4 receptor complex with an interleukin-4 molecule.


lateral cortical node

A protein complex that is anchored at the cortical face of the plasma membrane, and contains proteins involved in regulating cell cycle progression. In Schizosaccharomyces pombe, lateral cortical nodes are several megadaltons in size, and contain Slf1, which anchors the complex at the membrane, and the methyltransferase Skb1 in stoichiometric quantities, and may contain other proteins.


alpha,alpha-trehalose-phosphate synthase complex (UDP-forming)

A protein complex that possesses alpha,alpha-trehalose-phosphate synthase (UDP-forming) and trehalose-phosphatase activities, and thus catalyzes two reactions in trehalose biosynthesis. In the complex identified in Saccharomyces, Tps1p has alpha,alpha-trehalose-phosphate synthase (UDP-forming) activity, Tps2p has trehalose 6-phosphate phosphatase activity; Tps3p is a regulatory subunit, and an additional subunit, Tsl1p, may be present.


IgW immunoglobulin complex

A protein complex composed of two identical immunoglobulin heavy chains of the IgW isotype and two identical immunoglobulin light chains, held together by disulfide bonds. An IgW immunoglobulin complex may be embedded in the plasma membrane or present in the extracellular space, in mucosal areas or other tissues, or circulating in the blood or lymph.


alphaV-beta3 integrin-NOV complex

A protein complex that consists of an alphaV-beta3 integrin complex bound to the extracellular matrix protein NOV.


proton-transporting V-type ATPase complex

A proton-transporting two-sector ATPase complex that couples ATP hydrolysis to the transport of protons across a concentration gradient. The resulting transmembrane electrochemical potential of H+ is used to drive a variety of (i) secondary active transport systems via H+-dependent symporters and antiporters and (ii) channel-mediated transport systems. The complex comprises a membrane sector (V0) that carries out proton transport and a cytoplasmic compartment sector (V1) that catalyzes ATP hydrolysis. V-type ATPases are found in the membranes of organelles such as vacuoles, endosomes, and lysosomes, and in the plasma membrane.


G protein-coupled serotonin receptor complex

A protein complex that is capable of G protein-coupled serotonin receptor activity.


ciliary transition fiber

A nine-bladed, propeller-like protein complex that links the distal end of the basal body and the cilium to the plasma membrane. Functions in protein sorting and gating (i.e. active and passive transport of proteins in and out of the cilium).


TCR signalosome

A multi-protein complex containing at least the T-cell receptor complex and the LAT (linker for activation of T cells) scaffold protein. Also contains a variety of signaling proteins including co-receptors, kinases, phosphatases and adaptors such as CD8. Connects events on the plasma membrane to distal signaling cascades to ultimately modulate T cell biology.


nucleolar preribosome

Any complex of pre-rRNAs, ribosomal proteins, and associated proteins formed in the nucleolus during ribosome biogenesis.


oxoglutarate dehydrogenase complex

A complex of multiple copies of three enzymatic components: oxoglutarate dehydrogenase (lipoamide) (E1), dihydrolipoamide S-succinyltransferase (E2) and dihydrolipoamide dehydrogenase (E3); catalyzes the overall conversion of 2-oxoglutarate to succinyl-CoA and carbon dioxide (CO2).


collagen type XXIII trimer

A collagen homotrimer of alpha1(XXIII) chains; type XXIII collagen triple helices span the plasma membrane.


7SK snRNP

A ribonucleoprotein complex that contains the 7SK snRNA. The 7SK snRNP plays a central role in RNA polymerase II elongation control by regulating the availability of active P-TEFb.


A protein complex that consists of an alpha5-beta1 integrin complex bound to osteopontin.


9+0 non-motile cilium

A non-motile cilium where the axoneme has a ring of nine outer microtubule doublets but no central microtubules (and is therefore called a 9+0 axoneme).


ubiquitin ligase complex

A protein complex that includes a ubiquitin-protein ligase and enables ubiquitin protein ligase activity. The complex also contains other proteins that may confer substrate specificity on the complex.


alphaX-beta2 integrin-ICAM-4 complex

A protein complex that consists of an alphaX-beta2 integrin complex bound to intercellular adhesion molecule 4.


NAD(P)H dehydrogenase complex (plastoquinone)

Complex that possesses NAD(P)H dehydrogenase (plastoquinone) activity. The complex is one of the components of the electron transport chain. It is involved in electron transport from an unidentified electron donor, possibly NADH, NADPH or ferredoxin(Fd) to the plastoquinone pool.


ribonuclease P complex

A ribonucleoprotein complex that catalyzes cleavage of the leader sequence of precursor tRNAs (pre-tRNAs), generating the mature 5' end of tRNAs.


meiotic cohesin complex

A cohesin complex that mediates sister chromatid cohesion during meiosis; has a subunit composition distinct from that of the mitotic cohesin complex.


transcription factor TFIID complex

A complex composed of TATA binding protein (TBP) and TBP associated factors (TAFs); the total mass is typically about 800 kDa. Most of the TAFs are conserved across species. In TATA-containing promoters for RNA polymerase II (Pol II), TFIID is believed to recognize at least two distinct elements, the TATA element and a downstream promoter element. TFIID is also involved in recognition of TATA-less Pol II promoters. Binding of TFIID to DNA is necessary but not sufficient for transcription initiation from most RNA polymerase II promoters.


SLAC complex

A protein complex that regulates Arp2/3 complex-mediated actin nucleation.


tRNA-intron endonuclease complex

A protein complex that catalyzes the endonucleolytic cleavage of pre-tRNA, producing 5'-hydroxyl and 2',3'-cyclic phosphate termini, and specifically removing the intron.


sheet-forming collagen trimer

A protein complex consisting of three collagen chains assembled into a left-handed triple helix. These trimers assemble into a sheet.


urease complex

A multiprotein nickel-containing complex that possesses urease activity (catalysis of the hydrolysis of urea to ammonia and carbon dioxide).


endoplasmic reticulum palmitoyltransferase complex

A complex of the endoplasmic reticulum that catalyzes S-palmitoylation, the addition of palmitate (C16:0) or other long-chain fatty acids to proteins at a cysteine residue.


succinate-CoA ligase complex (ADP-forming)

A heterodimeric enzyme complex, composed of an alpha and beta chain, most usually found in (but not limited to) bacteria. Functions in the TCA cycle, hydrolyzing succinyl-CoA into succinate and CoA, thereby forming ATP.


amyloid-beta complex

Protein complex involved in modulation of signaling and synaptic function in the brain, predominantly in the cerebral cortex and hippocampus. Forms dimers and multimers of amyloid beta peptide 40 and peptide 42 (proteolytic cleavage products of amyloid beta A4 protein, also known as amyloid beta precursor protein). Mostly found in the extracellular space with a proportion occurring as membrane-bound species. Influences synaptic plasticity through various receptors, mediates dendritic spine loss leading to decreased synapse density, inhibits long-term potentiation (LTP) and enhances long-term depression (LTD). Soluble multimeric form is the main pathogenic species linked to Alzheimer's disease.


A protein complex which is capable of protein-cysteine S-palmitoyltransferase activity.


DNA ligase IV complex

A eukaryotically conserved protein complex that contains DNA ligase IV and is involved in DNA repair by non-homologous end joining; in addition to the ligase, the complex also contains XRCC4 or a homolog, e.g. Saccharomyces Lif1p.


TTT complex

A protein complex responsible for the stabilisation of protein levels of the phosphatidylinositol 3-kinase-related protein kinase (PIKK) family proteins. The TTT complex can also be found as part of the ASTRA complex (GO:0070209).


methylthiol:coenzyme M methyltransferase complex

A protein complex of two polypeptides which catalyzes the transfer of methyl group from methylthiol to coenzyme M during methanogenesis.


glucosidase II complex

A heterodimeric complex that catalyzes the trimming of glucose residues from N-linked core glycans on newly synthesized glycoproteins.


chloroplast proton-transporting ATP synthase complex, coupling factor CF(o)

All non-F1 subunits of the chloroplast hydrogen-transporting ATP synthase, including integral and peripheral chloroplast thylakoid membrane proteins.


alphav-beta3 integrin-ADAM15 complex

A protein complex that consists of an alphav-beta3 integrin complex bound to the transmembrane metallopeptidase ADAM15.


translocon complex

A protein complex that constitutes a specific site of protein translocation across the endoplasmic reticulum, which involves the signal recognition particle receptor. The complex contains a core heterotrimer of alpha, beta and gamma subunits, and may contain additional proteins.


peroxisomal importomer complex

A protein complex responsible for transporting proteins into the peroxisomal matrix. An example of this complex is Pex14 found in S. cerevisae which has 9 core components and 12 transient interaction partners.


IgA B cell receptor complex

An IgA immunoglobulin complex that is present in the plasma membrane of B cells and is composed of two identical immunoglobulin heavy chains of an IgA isotype and two identical immunoglobulin light chains and a signaling subunit, a heterodimer of the Ig-alpha and Ig-beta proteins.


PAS complex

A class III phosphatidylinositol 3-kinase complex that contains a phosphatidylinositol-3-phosphate 5-kinase subunit (Fab1p in yeast; PIKfyve in mammals), a kinase activator, and a phosphatase, and may also contain additional proteins; it is involved in regulating the synthesis and turnover of phosphatidylinositol 3,5-bisphosphate. In mammals the complex is composed of PIKFYVE, FIG4 and VAC14. In yeast it is composed of Atg18p, Fig4p, Fab1p, Vac14p and Vac7p.


TAP complex

A heterodimer composed of the subunits TAP1 and TAP2 (transporter associated with antigen presentation). Functions in the transport of antigenic peptides from the cytosol to the lumen of the endoplasmic reticulum.


SUMO activating enzyme complex

A conserved heterodimeric complex with SUMO activating enzyme activity.


chylomicron

A large lipoprotein particle (diameter 75-1200 nm) composed of a central core of triglycerides and cholesterol surrounded by a protein-phospholipid coating. The proteins include one molecule of apolipoprotein B-48 and may include a variety of apolipoproteins, including APOAs, APOCs and APOE. Chylomicrons are found in blood or lymph and carry lipids from the intestines into other body tissues.


laminin-14 complex

A laminin complex composed of alpha4, beta2 and gamma3 polypeptide chains.


inhibin-betaglycan-ActRII complex

A protein complex that consists of inhibin, type III transforming growth factor beta receptor (also known as betaglycan), and the type II activin receptor ActRII. The complex is thought to negatively regulate the activity of activin B.


APC-IQGAP1-CLIP-170 complex

A protein complex that contains the tumor suppressor protein adenomatous polyposis coli (APC), the small GTPase Cdc42, and CLIP-170; may play a role in cytoskeleton organization and cell migration.


Cul4B-RING E3 ubiquitin ligase complex

A ubiquitin ligase complex in which a cullin from the Cul4B subfamily and a RING domain protein form the catalytic core; substrate specificity is conferred by unknown subunits.


Kv4.2-KChIP3 channel complex

A voltage-gated potassium channel complex that contains the Kv channel interacting protein KChIP3 associated with the channel via interaction with the Kv alpha subunit 4.2.


transcription factor TFIIE complex

A transcription factor which in humans consists of a complex of two alpha and two beta chains. Recruits TFIIH to the initiation complex and helps activate both RNA polymerase II and TFIIH.


high-affinity iron permease complex

A protein complex composed of a multicopper ferroxidase that oxidizes Fe(II) to Fe(III), and a ferric iron permease that transports the produced Fe(III) into the cell. In high-affinity transport the transporter is able to bind the solute even if it is only present at very low concentrations.


IscS-IscU complex

A heterotetrameric protein complex involved in the sulfur transfer during iron-sulfur cluster assembly and in the modification of tRNA wobble positions. In E. coli it consisting of a central IscS dimer with the IscU protomers attached to one of the IscS units each via a disulfide (-SSH) group.


SL snRNP

A ribonucleoprotein complex that contains spliced leader (SL) RNA and associated proteins.


FHL2-CREB complex

A protein complex that contains CREB and FHL2, and is involved in transcriptional regulation.


FtsBL complex

A protein complex required for prokaryotic cell division (FtsZ-dependent cytokinesis). Part of the divisome. Assembled independently of the other divisome components in the cytoplasm prior to transport to the cell septum. In E. coli consists of FtsB and FtsL.


ripoptosome

A protein complex whose core components are the receptor-interacting serine/threonine-protein kinases RIPK1 and RIPK3 (also called RIP1 and RIP3). Formation of the ripoptosome can induce an extrinsic apoptotic signaling pathway or a necroptotic signaling pathway. The composition of this protein complex may depend on several factors including nature of the signal, cell type and more.


myosin complex

A protein complex, formed of one or more myosin heavy chains plus associated light chains and other proteins, that functions as a molecular motor; uses the energy of ATP hydrolysis to move actin filaments or to move vesicles or other cargo on fixed actin filaments; has magnesium-ATPase activity and binds actin. Myosin classes are distinguished based on sequence features of the motor, or head, domain, but also have distinct tail regions that are believed to bind specific cargoes.


thioglucosidase complex

A large (200-800 kDa) multiprotein complex formed by 70-kDa and 5-kDa myrosinases, myrosinase- binding proteins (MBPs), MBP-related proteins and myrosinase-associated proteins. The complex has been identified in Brassica napus seeds.


type III site-specific deoxyribonuclease complex

A heterodimeric enzyme complex composed of two subunits, Res and Mod, that functions as an endonuclease and cleaves DNA. Cleavage will only occur when there are two un-methylated copies of a specific recognition site in an inverse orientation on the DNA. Cleavage occurs at a specific distance away from one of the recognition sites. The Mod subunit can act alone as a methyltansferase. DNA restriction systems such as this are used by bacteria to defend against phage and other foreign DNA that may enter a cell.


Golgi transport complex

A multisubunit tethering complex of the CATCHR family (complexes associated with tethering containing helical rods) that has a role in tethering vesicles to the Golgi prior to fusion. Composed of 8 subunits COG1-8.


ciliary base

Area of the cilium (also called flagellum) where the basal body and the axoneme are anchored to the plasma membrane. The ciliary base encompasses the distal part of the basal body, transition fibers and transition zone and is structurally and functionally very distinct from the rest of the cilium. In this area proteins are sorted and filtered before entering the cilium, and many ciliary proteins localize specifically to this area.


interleukin-3 receptor complex

A protein complex that binds interleukin-3; comprises an alpha and a beta subunit. The alpha chain is specific to the interleukin-3 receptor, whereas the beta chain is shared with the receptors for granulocyte-macrophage colony-stimulating factor and interleukin-5.


CD95 death-inducing signaling complex

A protein complex formed upon binding of Fas/CD95/APO-1 to its ligand. The complex includes FADD/Mort1, procaspase-8/10 and c-FLIP in addition to the ligand-bound receptor.


tripartite ATP-independent periplasmic transporter complex

A complex consisting of two membrane proteins and one extracytoplasmic solute receptor. Such transporters transport a variety of substrates without direct ATP power, instead using energy from ion gradients.


ANPR-A receptor complex

A receptor complex composed of two ANPR-A molecules and expressed in the heart atrium in mammals; it plays a major role in the regulation of blood pressure and salt-fluid volume homeostasis. Binding of the ligand AMP in response to atrial distension (high blood volume) leads to guanylate cyclase activity of the ANPR-A receptor complex, thereby elevating intracellular cGMP levels. The end result is a reduction in blood volume and, therefore, a reduction in cardiac output and systemic blood pressure.


3-isopropylmalate dehydratase complex

A heterodimeric enzyme complex composed of subunits leuC and leuD. Catalyzes the isomerization between 2-isopropylmalate and 3-isopropylmalate, via the formation of 2-isopropylmaleate.


BID-BCL-2 complex

A heterodimeric protein complex consisting of BID and BCL-2, members of the Bcl-2 family of anti- and proapoptotic regulators.


sperm individualization complex

A macromolecular complex that includes cytoskeletal components and part of the cell membrane. Forms at the nuclear end of a male germline syncytium, or cyst, and translocates the over the length of the syncytium in the course of sperm individualization. Each complex contains an array of 64 investment cones, one per nucleus, that move synchronously along the spermatogenic cyst.


membrane fusion priming complex

A protein complex that primes vacuolar or vesicular membranes for fusion with other intracellular membranes, by promoting the dissociation of cis-SNARE complexes.


calpain complex

A calcium-dependent protease complex that processes its substrate by limited proteolysis rather than degrading it. In some cases limited proteolysis is required for the activation of its substrate.


A multienzyme, heterooligomeric complex involved in dolichyl-linked oligosaccharide synthesis. In yeast the complex is composed of Alg7p, which catalyzes the first step (GlcNAc1-PP-Dol from dolichol-phosphate and UDP-GlcNAc), and Alg13p plus Alg14p, the catalytic and anchoring subunits respectively, which together catalyze the second step (GlcNAc2-PP-dolichol from GlcNAc1-PP-Dol and UDP-GlcNAc) of dolichyl-linked oligosaccharide synthesis.


Wnt-Frizzled-LRP5/6 complex

A protein complex containing a secreted Wnt protein associated with its receptor, Frizzled (Fz), and co-receptor low density lipoprotein receptor-related protein 5 (LRP5) or LRP6.


sarcoglycan complex

A protein complex formed of four sarcoglycans plus sarcospan; there are six known sarcoglycans: alpha-, beta-, gamma-, delta-, epsilon- and zeta-sarcoglycan; all are N-glycosylated single-pass transmembrane proteins. The sarcoglycan-sarcospan complex is a subcomplex of the dystrophin glycoprotein complex, and is fixed to the dystrophin axis by a lateral association with the dystroglycan complex.


serine-type endopeptidase complex

A protein complex which is capable of serine-type endopeptidase activity.


Cdc42 GTPase complex

A protein complex formed by the association of the small GTPase Cdc42 with additional proteins. In Schizosaccharomyces the complex contains the Cdc42, Ras1, Scd1, Scd2, andShk1 proteins, and functions in the Ras1-Scd GTPase signalling pathway.


interferon regulatory factor complex

A protein complex that consists of two interferon regulatory proteins (IRFs); may be homodimeric or heterodimeric. The activation of a latent closed conformation of IRF in the cytoplasm is triggered by phosphorylation of Ser/Thr residues in a C-terminal region. Phosphorylation stimulates the C-terminal autoinhibitory domain to attain a highly extended conformation triggering dimerization through extensive contacts to a second subunit.


eukaryotic 43S preinitiation complex

A protein complex composed of the 40S ribosomal subunit plus eIF1, eIF1A, eIF3, eIF5, and eIF2-GTP-bound methionyl-initiator methionine tRNA.


retromer, cargo-selective complex

The trimeric subcomplex of the retromer, believed to be closely associated with the membrane. This trimeric complex is responsible for recognizing and binding to cargo molecules. The complex comprises three Vps proteins in both yeast and mammalian cells: Vps35p, Vps29p, and Vps26p in yeast, and VPS35, VPS29 and VPS26A or VPS26B in mammals.


alpha3-beta1 integrin-tissue transglutaminase complex

A protein complex that consists of an alpha3-beta1 integrin complex bound to tissue transglutaminase.


THO complex part of transcription export complex

The THO complex when it is part of the TREX (TRanscription EXport) complex that is involved in coupling transcription to export of mRNAs to the cytoplasm. In S. cerevisiae, it is composed of four subunits: Hpr1, Tho2, Thp1, and Mft1, while the human complex is composed of 7 subunits.


MIM complex

A large mitochondrial outer membrane translocase complex that mediates transport of proteins into mitochondrial compartments. MIM constitutes the major integration site for alpha-helical embedded proteins. In yeast, consists oof Mim1 and Mim2.


tubulobulbar complex

Actin-based structures involved in establishing close contact between Sertoli-Sertoli cells or Sertoli-spermatids in the seminiferous tubules of the testes.


alpha4-beta1 integrin-CD63 complex

A protein complex that consists of an alpha4-beta1 integrin complex bound to membrane protein CD63, a member of the tetraspan family.


alpha5-beta1 integrin-LPP3 complex

A protein complex that consists of an alpha5-beta1 integrin complex bound to lipid phosphate phosphohydrolase-3.


collagen trimer

A protein complex consisting of three collagen chains assembled into a left-handed triple helix. These trimers typically assemble into higher order structures.


RISC complex

A ribonucleoprotein complex that contains members of the Argonaute family of proteins, small interfering RNAs (siRNAs) or microRNAs (miRNAs), and miRNA or siRNA-complementary mRNAs, in addition to a number of accessory factors. The RISC complex is involved in posttranscriptional repression of gene expression through downregulation of translation or induction of mRNA degradation.


A protein complex which is capable of potassium:proton antiporter activity.


Cry-Per complex

Nuclear transcriptional repressor complex that is capable of negatively regulating CLOCK-BMAL-dependent transactivation of genes in a delayed negative feedback manner which generates circadian rhythms.


methyltransferase complex

A protein complex that possesses methyltransferase activity.


acyl-CoA ceramide synthase complex

A protein complex that catalyzes the reaction acyl-CoA + sphingosine = CoA + N-acylsphingosine. In S. cerevisiae it contains three subunits: lag1, lac1 and lip1.


Swr1 complex

A multisubunit protein complex that is involved in chromatin remodeling. It is required for the incorporation of the histone variant H2AZ into chromatin. In S. cerevisiae, the complex contains Swr1p, a Swi2/Snf2-related ATPase, and 12 additional subunits.


THO complex

The THO complex is a nuclear complex that is required for transcription elongation through genes containing tandemly repeated DNA sequences. The THO complex is also part of the TREX (TRanscription EXport) complex that is involved in coupling transcription to export of mRNAs to the cytoplasm. In S. cerevisiae, it is composed of four subunits: Hpr1p, Tho2p, Thp1p, and Mft1p, while the human complex is composed of 7 subunits.


ATP-binding cassette (ABC) transporter complex

A complex for the transport of metabolites into and out of the cell, typically comprised of four domains; two membrane-associated domains and two ATP-binding domains at the intracellular face of the membrane, that form a central pore through the plasma membrane. Each of the four core domains may be encoded as a separate polypeptide or the domains can be fused in any one of a number of ways into multidomain polypeptides. In Bacteria and Archaebacteria, ABC transporters also include substrate binding proteins to bind substrate external to the cytoplasm and deliver it to the transporter.


VCB complex

A protein complex that possesses ubiquitin ligase activity; the complex is usually pentameric; for example, in mammals the subunits are pVHL, elongin B, elongin C, cullin-2 (Cul2), and Rbx1.


Mei2 nuclear dot complex

A ribonucleoprotein complex that forms during meiotic prophase in a fixed position in the horsetail nucleus; contains Mei2 and meiRNA. May play a role in the progression of meiosis I.


pyrophosphate-dependent phosphofructokinase complex, beta-subunit complex

Refers to the beta subunit of the heterodimeric complex that possesses pyrophosphate-dependent phosphofructokinase activity.


DnaB-DnaC-DnaT-PriA-PriB complex

A protein-DNA complex consisting of the helicase loading complex DnaB-DnaC, replication restart proteins DnaT, PriA and PriB, and associated DNA. Involved in the restart of DNA replication after a stalled replication fork has been repaired.


mitochondrial mRNA editing complex

An mRNA editing complex found in the mitochondrion. The best characterized example is that of Trypanosoma brucei, which catalyzes the insertion and deletion of uridylates.


RCAF complex

A protein complex that facilitates the assembly of nucleosomes on to newly synthesized DNA. In Drosophila, the complex comprises ASF1 and histones H3 and H4.


BAK complex

An oligomeric protein complex consisting of BAK, a member of the Bcl-2 family of anti- and proapoptotic regulators.


collagen type XXVI trimer

A collagen homotrimer of alpha1(XXVI) chains.


protein complex involved in cell adhesion

Any protein complex that is capable of carrying out some part of the process of cell adhesion to the cell matrix or to another cell.


PSI associated light-harvesting complex I, LHCIb subcomplex

A pigment protein complex that forms part of the photosystem I associated light-harvesting complex I; contains two proteins (usually about 20 kDa); has a fluorescence maximum of 730 nm.


Rad51B-Rad51C complex

A DNA recombinase mediator complex that contains the Rad51 paralogs RAD51B and RAD51C, or orthologs thereof.


high molecular weight kininogen receptor complex

A protein complex that acts as a receptor for high molecular weight kininogens. In humans, this receptor includes the CK1 and uPAR proteins.


proteasome accessory complex

A protein complex, that caps one or both ends of the proteasome core complex and regulates entry into, or exit from, the proteasome core complex.


cobalamin transport complex

Protein complex facilitating ATP-dependent cobalamin (vitamin B12) transport through inner cell membrane (periplasm to cytoplasm) in Gram-negative bacteria. In E. coli the system is composed of a periplasmic cobalamin-binding protein (BtuF), an integral membrane homodimer, BtuC, and a cytoplasmic ATP-binding homodimer BtuD.


endopeptidase Clp complex

A protein complex comprised of members of the ClpX, ClpC, ClpD, ClpP or ClpR protein families. ClpPs are the proteolytic subunit of active complexes, and ClpA and ClpX form the regulatory subunits. Enzymatically active and inactive complexes can form.


respiratory chain complex III

A protein complex that transfers electrons from ubiquinol to cytochrome c and translocates two protons across a membrane. The complex contains a core structure of three catalytic subunits: cytochrome b, the Rieske iron sulfur protein (ISP), and cytochrome c1, which are arranged in an integral membrane-bound dimeric complex; additional subunits are present, and vary among different species.


nuclear RNA-directed RNA polymerase complex

A complex required for RNAi mediated heterochromatin assembly. In S. pombe this contains RNA-directed RNA polymerase, a putative helicase and a protein containing a pap25 associated domain.


procollagen-proline 4-dioxygenase complex, alpha(II) type

A procollagen-proline 4-dioxygenase complex that contains alpha subunits of the type II isoform; its activity is inhibited by poly(L-proline) only at high concentrations.


pyroptosome complex

A protein complex that consists of an assemble of ASC dimers that is capable of inducing pyroptosis.


DNA recombinase complex

A protein-DNA complex consisting of a higher-order oligomer of strand exchange proteins (recombinases) on single-stranded DNA.


protein C inhibitor-coagulation factor V complex

A heterodimeric protein complex that contains protein C inhibitor (SERPINA5) and coagulation factor V (F5); formation of the complex inhibits the serine protease activity of coagulation factor V.


SMN-Gemin2 complex

A protein complex that contains the survival motor neuron (SMN) protein and Gemin2; may form the stable core of the larger SMN complex.


Fc-alpha receptor I complex

A protein complex composed of an Fc-alpha R alpha chain and an Fc-epsilon RI gamma chain dimer with or without additional signaling components. The complex functions primarily as an activating receptor for IgA.


GID complex

A protein complex with ubiquitin ligase activity that, in Saccharomyces cerevisiae, is involved in proteasomal degradation of fructose-1,6-bisphosphatase (FBPase) and phosphoenolpyruvate carboxykinase during the transition from gluconeogenic to glycolytic growth conditions. It appears to play a broader role in cellular homeostasis and development in other species.


gamma-secretase complex

A protein complex that has aspartic-type endopeptidase activity and contains a presenilin catalytic subunit (either PSEN1 or PSEN2), an APH1 subunit (multiple genes and splice variants exist), nicastrin (NCT), and presenilin enhancer (aka PEN-2 or Psenen), as the core complex. Variants of the complex with different subunit compositions differ in localization and specific substrates. Additionally, variants of the complex exist that contain a additional regulatory subunit as well as the four core subunits; known regulatory subunits include gamma-secretase-activating protein (aka gSAP), TMP1 (aka TMED10), and CD147 antigen (aka basigin). Gamma-secretase cleaves type I transmembrane protein substrates, including the cell surface receptor Notch and the amyloid-beta precursor protein.


sulfite reductase complex (NADPH)

A multisubunit iron flavoprotein, which in yeast is composed of 2 alpha and 2 beta subunits. Catalyzes the reduction of sulfite to sulfide.


multimeric ribonuclease P complex

A ribonuclease P complex that generally contains a single RNA molecule and several protein molecules. Examples of this complex are found in Archaeal species.


vesicle tethering complex

Any protein complex that plays a role in vesicle tethering.


polycystin complex

A stable heterodimeric complex composed of polycystin-1 and polycystin-2.


box H/ACA scaRNP complex

A box H/ACA RNP complex that is located in the Cajal body of the nucleoplasm. In higher eukaryotes, box H/ACA RNP located in Cajal bodies mediate pseudouridylation of spliceosomal snRNAs.


nuclear protein-containing complex

A stable assembly of two or more macromolecules, i.e. proteins, nucleic acids, carbohydrates or lipids, in which at least one component is a protein and the constituent parts function together in the nucleus.


thylakoid light-harvesting complex

A thylakoid membrane complex of chlorophylls a and b together with chlorophyll a-b binding proteins. In addition, LHCs contain a number of other proteins, the function of which is speculative, together with accessory pigments. The LHCs capture and transfer energy to photosystems I and II. An example of this is found in Arabidopsis thaliana.


NOXA-BCL-2 complex

A heterodimeric protein complex consisting of NOXA and BCL-2, members of the Bcl-2 family of anti- and proapoptotic regulators.


transforming growth factor beta complex

A protein complex acting as ligand of the transforming growth factor beta receptor complex, typically a homodimer of any of the TFGbeta isoforms. The precursor of TGFbeta proteins is cleaved into mature TGFbeta and the latency-associated peptide (LAP), which remains non-covalently linked to mature TGFbeta rendering it inactive. TGFbeta is activated by dimerisation and dissociation of the LAP.


transcription-coupled nucleotide-excision repair, DNA damage recognition complex

A protein complex that is capable of identifying lesions in DNA on the actively transcribed strand of the DNA duplex as well as a small subset of lesions not recognized by the general nucleotide-excision repair pathway. The wide range of substrate specificity suggests that the repair complex recognizes distortions in the DNA helix. It subsequently recruits a nucleotide-excision repair, preincision complex.


lysosomal HOPS complex

Any HOPS complex that is part of a lysosomal membrane.


translation repressor complex

A protein complex which is capable of translation repressor activity.


retrograde transporter complex, Golgi to ER

Transporter complex that recognises, binds and returns endoplasmic reticulum (ER) resident proteins that have trafficked to Golgi compartments. Targets proteins lacking the HDEL motif recognised by COPI-coated vesicles.


AIP1-IRE1 complex

A protein complex consisting of IRE1 (inositol-requiring enzyme-1) bound to AIP1 (ASK1-interacting protein 1/DAB2-interacting protein).


galectin lattice

A non-stoichiometric protein complex formed by several galectins crosslinking glycosylated ligands to form a dynamic lattice. The galectin lattice modulates receptor kinase signaling and the functionality of membrane receptors, by regulating the diffusion, compartmentalization and endocytosis of plasma membrane glycoproteins and glycolipids.


interleukin-23 receptor complex

A protein complex that binds interleukin-23 and that consists of, at a minimum, a dimeric interleukin and its two receptor subunits as well as optional additional kinase subunits.


urease activator complex

A protein complex required for the activation of urease. Activator subunits dissociate before urease has catalytic function.


collagen type XIX trimer

A collagen homotrimer of alpha1(XIX) chains; type XIX collagen triple helices localize to basement membrane zones in differentiating muscle cells.


right caudal flagellum

A cilium (also called flagellum) found in Giardia species (trophozoite stage). It is nucleated by the right caudal basal body, extending cytoplasmically and exiting at the posterior end of the cell body.


HCN channel complex

A cation ion channel with a preference for K+ over Na+ ions, which is activated by membrane hyperpolarization, and consists of a tetramer of HCN family members. Some members of this family (HCN1, HCN2 and HCN4) are also activated when cAMP binds to their cyclic nucleotide binding domain (CNBD). Channel complexes of this family play an important role in the control of pacemaker activity in the heart.


single-stranded DNA-binding protein complex

A homotetrameric protein complex that is essential for DNA replication. It supercoils the single-stranded DNA preventing DNA duplexing before the polymerase holoenzyme passes and synthesizes the complementary strand. It is also involved in DNA recombination and repair.


mitochondrial fatty acid beta-oxidation multienzyme complex

A complex that includes the long-chain 3-hydroxyacyl-CoA dehydrogenase and long-chain enoyl-CoA hydratase activities in two subunits (alpha and beta), catalyzing two steps of the fatty acid beta-oxidation cycle within the mitochondrial matrix.


photoreceptor cell cilium

A specialised 9+0 non-motile cilium found in photoreceptor cells. A ciliary transition zone called 'photoreceptor connecting cilium' links the photoreceptor outer segment to the inner segment.


viral terminase complex

A complex of a large and small subunit which catalyze the packaging of DNA into viral heads. Note that not all viral terminases have this structure, some exist as single polypeptides.


plasma membrane proton-transporting ATP synthase, central stalk

One of two stalks that connect the catalytic core of the hydrogen-transporting ATP synthase to the plasma membrane-associated Fo proteins; rotates within the catalytic core during catalysis. Examples of this component are found in Bacterial species.


U6 snRNP

A ribonucleoprotein complex that contains small nuclear RNA U6, the Lsm2-8 heptameric ring complex, as well as several proteins that are unique to the U6 snRNP, most of which remain associated with the U6 snRNA both while the U6 snRNP is free or assembled into the U4/U6 snRNP or into a series of spliceosomal complexes.


single-stranded DNA-dependent ATP-dependent DNA helicase complex

A protein complex that possesses single-stranded DNA-dependent DNA helicase activity.


Scrib-APC complex

A protein complex that contains the Scribble protein (a cell polarity determinant) and the tumor suppressor protein adenomatous polyposis coli (APC); may be involved in the control of cell proliferation.


SCF-Hrt3/Pof7 ubiquitin ligase complex

An SCF ubiquitin ligase complex in which the F-box protein is Hrt3 in S. cerevisiae (Pof7 in S. pombe).


beta-galactosidase complex

A protein complex that possesses beta-galactosidase activity, i.e. catalyzes the hydrolysis of terminal non-reducing beta-D-galactose residues in beta-D-galactosides. In E. coli, the complex is a homotetramer; dimeric and hexameric beta-galactosidase complexes have been observed in other species.


integrin alpha10-beta1 complex

An integrin complex that comprises one alpha10 subunit and one beta1 subunit.


nuclear proteasome core complex, alpha-subunit complex

The subunits forming the outer ring of the core complex of a proteasome located in the nucleus of a cell.


subapical complex

The most apical region of the lateral plasma membrane of an invertebrate epithelial cell. The subapical complex lies above the zonula adherens and the septate junction, and is comparable to the position of the tight junction of vertebrate cells.


Vps55/Vps68 complex

A membrane-associated protein complex that is required for a late stage of endosomal transport. In budding yeast, this complex consists of Vps55p and Vps68p proteins.


SREBP-SCAP-Insig complex

A protein complex formed by the association of sterol regulatory element binding protein (SREBP), SREBP-cleavage-activating protein (SCAP), and an Insig protein (Insig-1 or Insig-2) in the ER membrane.


PCNA complex

A protein complex composed of three identical PCNA monomers, each comprising two similar domains, which are joined in a head-to-tail arrangement to form a homotrimer. Forms a ring-like structure in solution, with a central hole sufficiently large to accommodate the double helix of DNA. Originally characterized as a DNA sliding clamp for replicative DNA polymerases and as an essential component of the replisome, and has also been shown to be involved in other processes including Okazaki fragment processing, DNA repair, translesion DNA synthesis, DNA methylation, chromatin remodeling and cell cycle regulation.


Fc-epsilon receptor I complex

A protein complex composed of an Fc-epsilon RI alpha chain and an Fc-epsilon RI gamma chain dimer with or without an Fc-episilon RI beta chain and additional signaling components. The complex functions primarily as an activating receptor for IgE.


multivesicular body HOPS complex

Any HOPS complex that is part of a multivesicular body membrane.


mitochondrial respiratory chain complex I, membrane segment

The mitochondrial membrane segment of respiratory chain complex I. Respiratory chain complex I is an enzyme of the respiratory chain, consisting of at least 34 polypeptide chains. The electrons of NADH enter the chain at this complex. The complete complex is L-shaped, with a horizontal arm lying in the membrane and a vertical arm that projects into the matrix.


cytosolic tRNA wobble base thiouridylase complex

A complex of two proteins involved in the thiolation of uridine 34 (U34) of tRNAs decoding two-family box triplets.


SAGA-type complex

A histone acetyltransferase complex that acetylates nucleosomal histones H2B, H3, or H4 and is required for the expression of a subset of Pol II-transcribed genes. This complex includes the acetyltransferases GCN5/KAT2A or PCAF/KAT2B, several proteins of the ADA, SGF and SPT families, and several TBP-associate proteins (TAFs).


copper ion transmembrane transporter complex

A protein complex which is capable of copper ion transmembrane transporter activity.


COPI vesicle coat

One of two multimeric complexes that forms a membrane vesicle coat. The mammalian COPI subunits are called alpha-, beta-, beta'-, gamma-, delta-, epsilon- and zeta-COP. Vesicles with COPI coats are found associated with Golgi membranes at steady state.


Noc4p-Nop14p complex

A heterodimer associated with precursors of the eukaryotic small ribosomal subunit, including the 90S preribosome; involved in small subunit biogenesis.


proteasome regulatory particle, base subcomplex

The subcomplex of the proteasome regulatory particle that directly associates with the proteasome core complex.


protein phosphatase 4 complex

A protein serine/threonine phosphatase complex formed by the catalytic subunit of protein phosphatase 4 plus one or more regulatory subunits.


interleukin-18 receptor complex

A protein complex that binds interleukin-18; comprises an alpha and a beta subunit.


intracellular cyclic nucleotide activated cation channel complex

A protein complex that forms a transmembrane channel through which cations ions may pass in response to an intracellular cyclic nucleotide binding to the channel complex or one of its constituent parts.


Noc2p-Noc3p complex

A heterodimer associated with 66S preribosomes; predominantly nucleoplasmic, but also locates to the nucleolus; involved in ribosomal large subunit biogenesis.


collagen type XV trimer

A collagen homotrimer of alpha1(XV) chains; a chondroitin sulfate proteoglycan often found in specialized basement membranes where it bridges between fibrils.


alpha9-beta1 integrin-ADAM3 complex

A protein complex that consists of an alpha9-beta1 integrin complex bound to the transmembrane metallopeptidase ADAM3.


mitochondrial respiratory chain complex IV

A protein complex located in the mitochondrial inner membrane that forms part of the mitochondrial respiratory chain. Contains the 13 polypeptide subunits of cytochrome c oxidase, including cytochrome a and cytochrome a3. Catalyzes the oxidation of reduced cytochrome c by dioxygen (O2).


interferon regulatory factor 3-interferon regulatory factor 5 complex

An interferon regulatory factor complex that consists of a heterodimer of interferon regulatory factor 3 and interferon regulatory factor 5.


nuclear aryl hydrocarbon receptor complex

An aryl hydrocarbon receptor (AhR) complex found in the nucleus; ; consists of ligand-bound AhR and the aryl hydrocarbon receptor nuclear translocator (ARNT).


glucose transporter complex

A protein complex facilitating glucose transport into, out of or within a cell, or between cells.


junctional membrane complex

Complex formed in muscle cells between the membrane of the sarcoplasmic reticulum and invaginations of the plasma membrane (T-tubules).


Cvt complex

A protein complex that is involved in the Cvt pathway. In budding yeast, the Cvt complex consists of multimers of preApe1p.


DASH complex

A large protein complex, containing around 8-10 subunits in yeast, including Duo1p, Dam1p, Dad1p and Ask1p. The complex forms part of the outer kinetochore, associates with microtubules when the kinetochore attaches to the spindle, and plays a role in spindle attachment, chromosome segregation and spindle stability.


SCF-Saf1/Pof9 ubiquitin ligase complex

An SCF ubiquitin ligase complex in which the F-box protein is Saf1 in S. cerevisiae (Pof9 in S. pombe).


mitochondrial large ribosomal subunit

The larger of the two subunits of a mitochondrial ribosome. Two sites on the ribosomal large subunit are involved in translation: the aminoacyl site (A site) and peptidyl site (P site).


stereocilia ankle link complex

A complex of proteins that connect growing stereocilia in developing cochlear hair cells, composed of Vlgr1, usherin, vezatin, and whirlin.


A protein complex that consists of an alphav-beta5 integrin complex bound to osteopontin.


A protein complex capable of protein N-acetylglucosaminyltransferase activity, the addition of nucleotide-activated sugars onto the polypeptide according to reaction: UDP-N-acetyl-D-glucosamine + protein = UDP + 4-N-(N-acetyl-D-glucosaminyl)-protein. The complex has different compositions in different species: In mammals it is often a homotrimer, in bacteria a heterotetramer of 2 different subunits.


exon-exon junction complex

A multi-subunit complex deposited by the spliceosome upstream of messenger RNA exon-exon junctions. The exon-exon junction complex provides a binding platform for factors involved in mRNA export and nonsense-mediated mRNA decay.


telomerase catalytic core complex

The minimal catalytic core of telomerase is a ribonucleoprotein complex composed of a catalytic reverse transcriptase subunit and an RNA subunit that provides the template for telomeric DNA addition.


follicle-stimulating hormone complex

A gonadotrophic glycoprotein hormone secreted, in mammals, by the anterior pituitary gland; consists of alpha and beta subunits, the latter of which confers hormonal specificity.


SCF-Rcy1/Pof6 ubiquitin ligase complex

An SCF ubiquitin ligase complex in which the F-box protein is Rcy1 in S. cerevisiae (Pof6 in S. pombe).


dystroglycan complex

A protein complex that includes alpha- and beta-dystroglycan, which are alternative products of the same gene; the laminin-binding component of the dystrophin-associated glycoprotein complex, providing a link between the subsarcolemmal cytoskeleton (in muscle cells) and the extracellular matrix. Alpha-dystroglycan is an extracellular protein binding to alpha-laminin and to beta-dystroglycan; beta-dystroglycan is a transmembrane protein which binds alpha-dystroglycan and dystrophin.


SMAD protein complex

A protein complex that consists of only SMAD proteins; may be homomeric or heteromeric. Heteromeric complexes act as transcription factors while homomeric complexes exist but are transcriptionally inactive. Hetero- versus homotrimerization is largely enthalpy driven.


tRNA-splicing ligase complex

A protein complex that catalyzes the ligation of cleaved pre-tRNAs by directly joining spliced tRNA halves to mature-sized tRNAs by incorporating the precursor-derived splice junction phosphate into the mature tRNA as a canonical 3',5'-phosphodiester.


L-cysteine desulfurase complex

A protein complex capable of cysteine desulfurase activity decomposing L-cysteine to L-alanine and sulfur. It belongs to a ubiquitous family of pyridoxal 5-phosphate (PLP)-dependent enzymes. In E. coli it consists of a SufS dimer.


Slx1-Slx4 complex

A heterodimeric protein complex that possesses an endonuclease activity that specifically cleaves certain types of branched DNA structures; because such structures often form during the replication ribosomal DNA (rDNA) repeats, the complex plays a role in the maintenance of rDNA. The subunits are known as Slx1 and Slx 4 in budding and fission yeasts, and are conserved in eukaryotes.


TERT-RMRP complex

A ribonucleoprotein complex that has RNA-directed RNA polymerase (RdRP) activity, and is composed of telomerase reverse transcriptase (TERT) and the non-coding RNA component of mitochondrial RNA processing endoribonuclease (RMRP).


membrane coat

Any of several different proteinaceous coats that can associate with membranes. Membrane coats include those formed by clathrin plus an adaptor complex, the COPI and COPII complexes, and possibly others. They are found associated with membranes on many vesicles as well as other membrane features such as pits and perhaps tubules.


TRAPPIII protein complex

A complex that functions in anterograde transport at the Golgi and also regulates autophagy. In yeast it includes at least the following subunits: Bet3 (as homodimer), Bet5, Trs20, Trs23, Trs31, Trs33, Trs85. TRAPPIII may include further, as yet undescribed, proteins.


MAML1-RBP-Jkappa- ICN1 complex

A protein complex that consists of the intracellular domain of Notch1 (ICN1), the DNA-binding transcription factor RBP-Jkappa, and the transcriptional coactivator Mastermind-like-1 (MAML1); the complex is involved in transcriptional activation in response to Notch-mediated signaling.


Kv4.2-KChIP1 channel complex

A voltage-gated potassium channel complex that contains the Kv channel interacting protein KChIP1 associated with the channel via interaction with the Kv alpha subunit 4.2.


BAT3 complex

A protein complex found in mammals that transfers tail-anchored (TA) proteins from SGTA to GET3 (ASNA1/TRC4) for targeting to the endoplasmic reticulum membrane. Also chaperones polypeptides from the endoplasmic reticulum retrotranslocation machinery to the proteasome, maintaining the solubility of substrates to improve ER-associated protein degradation (ERAD). Consists of BAG6 (BAT3) and its cofactors GET4 (TRC35) and UBL4A.


endobrevin-SNAP-25-syntaxin-1a complex

A SNARE complex that contains endobrevin (VAMP8), SNAP-25, and syntaxin 1a (or orthologs thereof).


D-amino-acid dehydrogenase complex

A protein complex that possesses D-amino-acid dehydrogenase activity.


divisome complex

A protein complex required for prokaryotic cell division (FtsZ-dependent cytokinesis). These complexes are assembled and recruited to the cell septum in a strictly controlled sequence and co-ordinate invagination of the cell membrane, inward growth of the peptidoglycan layer, constriction of the outer membrane and separation of daughter cells.


signal peptidase complex

A protein complex that is located in the endoplasmic reticulum membrane and cleaves the signal sequence from precursor proteins following their transport out of the cytoplasmic space.


ammonium transmembrane transporter complex

High affinity ammonium transporter complex that enables the transfer of ammonium from one side of a membrane to the other.


vesicle coat

A membrane coat found on a coated vesicle.


membrane protein complex

Any protein complex that is part of a membrane.


B875 antenna complex

Protein complex that surrounds and transfers excitation energy directly to the bacterial reaction center; binds bacteriochlorophyll a and has a single absorption band between 870 and 890 nm.


interleukin-28 receptor complex

A protein complex that binds interleukin-28 and interleukin-29. It is composed of an alpha and a beta receptor subunit (in human IFNLR1/IL28Ralpha & IL10RB) and either Interleukin-28 (IFNL2 or IFNL3) or Interleukin-29 (IFNL1).


interleukin-4 receptor complex

A protein complex that binds interleukin-4 (IL-4) and consists of an alpha chain that binds IL-4 with high affinity and a gamma common chain that also forms part of the interleukin-2 receptor.


tRNA methyltransferase complex

A multimeric protein complex involved in the methylation of specific nucleotides in tRNA.


4-aminobutyrate transaminase complex

A homodimeric protein complex that possesses 4-aminobutyrate transaminase activity.


Mst2 histone acetyltransferase complex

A protein complex that can catalyze the acetylation of lysine at position 14 in histone H3, and contains Mst2 as the catalytic subunit. In fission yeast, contains at least Mst2, Nto1, Ptf2, Ptf1 and Eaf6.


integrin alphav-beta1 complex

An integrin complex that comprises one alphav subunit and one beta1 subunit.


dimethyl sulfoxide reductase complex

An enzyme complex that catalyzes the formation of dimethyl sulfide from dimethyl sulfoxide.


RNA polymerase II termination complex

A conserved protein complex capable of 5'-3' exoribonuclease activity. It is able to promote RNA polymerase II (RNAPII) transcription termination by degrading pre-mRNA from the newly formed 5' phosphorylated end.


meiotic septin complex

A heterooligomeric septin complex that acts during meiotic cell division.


Cbp3p-Cbp6 complex

A protein complex located at the mitochondrial ribosome tunnel exit that is involved in efficient translation and protein complex assembly.


TSC1-TSC2 complex

A protein complex consisting of at least tumerin and hamartin; its formation may regulate hamartin homomultimer formation. The complex acts as a GTPase activating protein (GAP) for the small GTPase (Rheb), and inhibits the TOR signaling pathway.


inaD signaling complex

A complex of proteins that are involved in phototransduction and attached to the transient receptor potential (TRP) channel. The protein connections are mediated through inaD.


chloroplast photosystem II

An integral chloroplast membrane complex containing the P680 reaction center. In the light, PSII functions as a water-plastoquinone oxidoreductase, transferring electrons from water to plastoquinone.


integrin alpha1-beta1 complex

An integrin complex that comprises one alpha1 subunit and one beta1 subunit.


nuclear pore outer ring

A subcomplex of the nuclear pore complex (NPC) that forms the outer rings of the core scaffold, a lattice-like structure that gives the NPC its shape and strength. In S. cerevisiae, the two outer rings each contain multiple copies of the following proteins: Nup133p, Nup120p, Nup145Cp, Nup85p, Nup84p, Seh1p, and Sec13p. In vertebrates, the two outer rings each contain multiple copies of the following proteins: Nup133, Nup160, Nup96, Nup75, Nup107, Seh1, Sec13, Nup43, Nup37, and ALADIN. Components are arranged in 8-fold symmetrical 'spokes' around the central transport channel. A single 'spoke', can be isolated and is sometimes referred to as the Nup84 complex (S. cerevisiae) or the Nup107-160 complex (vertebrates).


SCF-Das1 ubiquitin ligase complex

An SCF ubiquitin ligase complex in which the F-box protein is Das1 in S. cerevisiae.


transcription factor AP-1 complex

A heterodimeric transcription factor complex composed of proteins from the c-Fos, c-Jun, activating transcription factor (ATF) or JDP families. The subunits contain a basic leucine zipper (bZIP) domain that is essential for dimerization and DNA binding. Jun-Fos heterodimers bind preferentially to a heptamer consensus sequence (TPA responsive element (TRE)), whereas Jun-ATF dimers bind the cyclic AMP responsive element (CRE) to regulate transcription of target genes.


Rad51C-XRCC3 complex

A DNA recombinase mediator complex that contains the Rad51 paralogs RAD51C and XRCC3, or orthologs thereof.


NADPH oxidase complex

A enzyme complex of which the core is a heterodimer composed of a light (alpha) and heavy (beta) chain, and requires several other water-soluble proteins of cytosolic origin for activity. Functions in superoxide generation by the NADPH-dependent reduction of O2.


Lid2 complex

A protein complex involved in regulation of chromatin remodeling. In Schizosaccharomyces the complex contains Lid2, Ash2, Jmj3, Snt2, and Sdc1.


Myc-Max complex

A transcription factor complex that consists of a heterodimer of the bHLH-ZIP proteins Myc and Max.


chloroplast isoamylase complex

A protein complex whose composition varies amongst species; in rice it probably exists in a homo-tetramer to homo-hexamer form and in Gram negative bacteria as a dimer. Functions in the hydrolysis of alpha-(1,6)-D-glucosidic branch linkages. Isoamylases in plants are intracellular and probably chloroplast localized.


Sec61 translocon complex

A translocon complex that contains a core heterotrimer of conserved alpha, beta and gamma subunits, and may contain additional proteins (translocon-associated proteins or TRAPs); in budding yeast the core proteins are Sec61p, Sbh1p, and Sss1p. The Sec61 translocon complex functions in cotranslational and posttranslational translocation events.


bI4 intron splicing complex

A protein complex required for the splicing of intron 4 of the cytochrome b (COB) gene. In S. cerevisiae, the complex contains the maturase bI4 (which derives from one of the products of the splicing), Leucyl-tRNA synthetase NAM2 and the intron 4 of the cytochrome b pre-mRNA. The two proteins stimulate the ribozyme activity of the pre-mRNA which autoctalyse a group I intron splicing.


tRNA (m2G10) methyltransferase complex

A protein complex required for the methylation of the guanosine nucleotide at position 10 (m2G10) in tRNA. In S. cerevisiae, this complex consists of at least two subunits, Trm11p and Trm112p.


nuclear membrane complex Bqt3-Bqt4

A protein complex that resides in the inner nuclear membrane and anchors telomeres to the nuclear envelope. In fission yeast, it is composed of Bqt3 and Bqt4.


RNA nuclear export complex

A complex which usually consists of three components, e.g. in Xenopus and yeast, the export receptor CRM1 (also known as exportin 1), the Ran protein and any RNA with a nuclear export sequence (NES). The complex acts to export RNA molecules with a NES from the nucleus through a nuclear pore.


Derlin-1 retrotranslocation complex

A protein complex that functions in the retrotranslocation step of ERAD (ER-associated protein degradation), and includes at its core Derlin-1 oligomers forming a retrotranslocation channel.


Pwp2p-containing subcomplex of 90S preribosome

A protein complex that forms a subcomplex of the 90S preribosome and can interact directly with the 5' External Transcribed Spacer (ETS) of the full length pre-rRNA transcript. In S. cerevisiae, it sediments at 25-30 S and is composed of Pwp2p, Dip2p, Utp21p, Utp13p, Utp18p, and Utp6p.


endoplasmic reticulum Sec complex

An endoplasmic reticulum membrane-associated complex involved in the translocation of proteins that are targeted to the ER. In yeast, this complex consists of two subcomplexes, namely, the Sec61 complex and the Sec62/Sec63 complex.


SUMO ligase complex

A protein ligase complex that enables protein sumoylation. Consists of a SUMO-protein transferase and other proteins that may confer substrate specificity of the complex.


plasma membrane-derived thylakoid photosystem II

A protein complex, located in the membrane-derived thylakoid, containing the P680 reaction center. In the light, PSII functions as a water-plastoquinone oxidoreductase, transferring electrons from water to plastoquinone.


tRNA-specific adenosine-34 deaminase complex

A protein complex that possesses tRNA-specific adenosine-34 deaminase activity. In eukaryotes the complex is a heterodimer; the subunits are known as Tad2p and Tad3p in yeasts and Adat2 and Adat3 in human.


interleukin-23 complex

A protein complex that is composed of an interleukin-23 alpha (p19, product of the IL23A gene) and an interleukin-12 beta (p40, product of the IL12B gene) subunit and is secreted into the extracellular space.


HIR complex

A protein complex proposed to be involved in replication-independent nucleosome assembly, by promoting histone deposition onto DNA. For example, in Saccharomyces, the complex contains Hir1p, Hir2p, Hir3p, and Hpc2p.


Bcl3-Bcl10 complex

A protein complex containing Bcl3 and Bcl10, which forms when Akt1 is activated by TNF-alpha to phosphorylate Bcl10; the Bcl3-Bcl10 complex is translocated to the nucleus.


A protein complex that catalyzes the formation of procollagen trans-4-hydroxy-L-proline and succinate from procollagen L-proline and 2-oxoglutarate, requiring Fe2+ and ascorbate. Contains two alpha subunits that contribute to most parts of the catalytic sites, and two beta subunits that are identical to protein-disulfide isomerase.


collagen type XX trimer

A collagen homotrimer of alpha1(XX) chains.


starch utilization system complex

A bacterial cell envelope-associated multiprotein system, which binds and degrades starch.


I-kappaB/NF-kappaB complex

A protein complex containing an inhibitory-kappaB (I-kappaB/IKB) protein and one or more copies of an NF-kappaB protein. In the resting state, NF-kappaB dimers are bound to I-kappaB proteins, sequestering NF-kappaB in the cytoplasm.


A SNARE complex that contains cellubrevin (VAMP3), VAMP4, endobrevin (VAMP8), and syntaxin 6 (or orthologs thereof).


large ribosomal subunit pre-assembly complex

A protein complex that assists early maturation of nascent 60S ribosomal subunits. The complex interacts with the large ribosomal subunit rRNA via one of the components (Urb2 in S. cerevisiae) and requires a RNA helicase (Dbp6 in S. cerevisiae).


replication inhibiting complex

A protein complex that inhibits multiple events of replication initiation during one replication cycle.


A heterodimer which catalyses the reaction of 5-amino-6-(D-ribitylamino)uracil and 4-hydroxyphenylpyruvate to form 7,8-didemethyl-8-hydroxy-5-deazariboflavin (FO), an intermediate of coenzyme F420.


Ost-alpha/Ost-beta complex

A heterodimeric protein complex composed of Ost-alpha/SLC51A and Ost-beta/SLC51B subunits and involved in bile acid transport activity.


MSL complex

A histone acetyltransferase complex that catalyzes the acetylation of a histone H4 lysine residue at position 16. In human, it contains the catalytic subunit MOF, and MSL1, MSL2 and MSL3.


phosphatidylinositol 3-kinase complex, class I

A phosphatidylinositol 3-kinase complex that contains a catalytic and a regulatory subunit of a phosphatidylinositol 3-kinase (PI3K) enzyme, plus one or more adaptor proteins. Class I PI3Ks phosphorylate phosphatidylinositol [PI], phosphatidylinositol-4-phosphate [PI(4)P] and phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2], and are divided into subclasses A and B according to the type of adaptor subunit with which they associate. The class I PI3K subfamily of genes comprises members in vertebrates, worm and fly, but none in yeast.


TRAPPI protein complex

A complex that tethers COPII vesicles at ER-Golgi intermediate compartment. Its role in this part of the vesicular transport may start at the ER exit sites. Binds to a component of the COPII coat. In yeast it includes the following subunits: Bet3 (as homodimer), Bet5, Trs20, Trs23, Trs31, Trs33 which are regarded as the core subunits of all TRAPP complexes in yeast.


homodimeric serine palmitoyltransferase complex

A homodimeric complex which transfers a palmitoyl group onto serine, forming 3-dehydro-D-sphinganine.


MCM core complex

A protein complex that contains Mcm4, Mcm6, and Mcm7 proteins, and possesses DNA helicase activity. In the heterohexameric MCM complex, the Mcm4/6/7 proteins form a stable core, and Mcm2, Mcm3, and Mcm5 are more peripherally associated.


IgD B cell receptor complex

An IgD immunoglobulin complex that is present in the plasma membrane of B cells and is composed of two identical immunoglobulin heavy chains of the IgD isotype and two identical immunoglobulin light chains and a signaling subunit, a heterodimer of the Ig-alpha and Ig-beta proteins.


proton-transporting ATP synthase, central stalk

One of two stalks that connect the catalytic core of the hydrogen-transporting ATP synthase to the membrane-associated Fo proteins; rotates within the catalytic core during catalysis.


MBF transcription complex

A protein complex that binds to the Mlu1 cell cycle box (MCB) promoter element, consensus sequence ACGCGN, and is involved in regulation of transcription during the G1/S transition of the cell cycle. In Saccharomyces, the complex contains a heterodimer of the DNA binding protein Mbp1p and the activator Swi6p, and is associated with additional proteins known as Nrm1p, Msa1p, and Msa2p; in Schizosaccharomyces the complex contains Res1p, Res2p, and Cdc10p.


A protein complex that possesses UDP-N-acetylglucosamine-lysosomal-enzyme N-acetylglucosaminephosphotransferase activity; the bovine complex contains disulfide-linked homodimers of 166- and 51-kDa subunits and two identical, noncovalently associated 56-kDa subunits.


DNA-dependent protein kinase-DNA ligase 4 complex

A large protein complex which is involved in the repair of DNA double-strand breaks and, in mammals, V(D)J recombination events. It consists of the DNA-dependent protein kinase catalytic subunit (DNA-PKcs), the DNA end-binding heterodimer Ku, the nuclear phosphoprotein XRCC4 or a homolog thereof, and DNA ligase IV.


SHREC2 complex

A histone deacetylase complex formed by the association of an HP1 protein with a SHREC complex. The SHREC2 complex is required for deacetylation of H3K14, and mediates transcriptional gene silencing by limiting RNA polymerase II access to heterochromatin. In fission yeast, the complex contains the SHREC subunits Clr1, Clr2, Clr3, and Mit1, and the HP1 protein Chp2.


outer dynein arm docking complex

A complex which stabilizes the binding of and correctly positions the outer dynein arm complex along an A-tubule of the flagellar axoneme outer doublet microtubules.


A protein complex that consists of an alpha2-beta1 integrin complex bound to the cartilage matrix protein chondroadherin.


AMPA glutamate receptor complex

An assembly of four or five subunits which form a structure with an extracellular N-terminus and a large loop that together form the ligand binding domain. The C-terminus is intracellular. The ionotropic glutamate receptor complex itself acts as a ligand gated ion channel; on binding glutamate, charged ions pass through a channel in the center of the receptor complex. The AMPA receptors mediate fast synaptic transmission in the CNS and are composed of subunits GluR1-4, products from separate genes. These subunits have an extracellular N-terminus and an intracellular C-terminus.


origin recognition complex

A multisubunit complex that is located at the replication origins of a chromosome.


anchoring collagen complex

Any collagen complex which links one collagen assembly, such as a collagen fibril or sheet, to other structures.


chloroplast proton-transporting ATP synthase complex

A proton-transporting ATP synthase complex found in the chloroplast thylakoid membrane; it catalyzes the phosphorylation of ADP to ATP during photo-phosphorylation.