A hot spot for RAD51C interactions revealed by a peptide that sensitizes cells to cisplatin.

DNA repair via the homologous recombination pathway requires the recombinase RAD51 and, in vertabrates, five RAD51 paralogs. The paralogs form two complexes in solution, a XRCC3/RAD51C heterodimer and a RAD51B/RAD51C/RAD51D/XRCC2 heterotetramer. Mutation of any one of the five paralog genes prevents subnuclear assembly of recombinase at damaged sites and renders cells 30-100 fold sensitive to DNA cross-linking drugs.