geranylgeranyltransferase type III activity
geranylgeranyltransferase type iii activity
Catalyzes the covalent addition of a geranylgeranyl group to a mono-farnesylated substrate via a thioether linkage to a cysteine residue located within a conserved C-terminal tandem cysteine motif (CCAIM or CCIIM) that is used in substrate recognition. Known substrates include mono-farnesylated Golgi SNARE proteins.