BRCA1 C complex
brca1 c complex
BRCA1 forms a complex with RBBP8 and MRN (MRE11/RAD50/NBN) in a cell cycle-dependent manner during S and G2 phase of the cell cycle through the BRCT domains of BRCA1 binding to phosphorylated S327, a CDK phosphorylation site of RBBP8 in a phospho-SPxF motif. The <a href='http://www.genenames.org/data/genegroup/#!/group/1344'>MRN complex</a> also has other functions not related to its role in the BRCA1 C complex.  RBBP8 is required for DNA end resection at the initial step of homologous recombination (HR) dependent DSB repair CTIP promotes DNA end resection by interacting and stimulating the nuclease activity of the MRN complex. The complex formation of BRCA1-RBBP8-MRN is important for facilitating DSB resection to generate single-stranded DNA that is needed for HR-mediated DSB repair.