hSSB1, RPA, and BRCA2 are essential SSBs in the repair of double strand DNA breaks (DSBs) by homologous recombination. A potential model for human SSBs in the repair of DSBs: The MRN complex is initially recruited to sites of DSBs by hSSB1, allowing for resection of the 5′ strand. ssDNA stretches are rapidly bound by RPA, which, following BRCA2-DNA binding, is removed to allow for RAD51 nucleofilament formation. Homologous recombination is then facilitated by RAD51–mediated strand invasion into a sister chromatid. hSSB1 has also been found to interact directly with RAD51 and to facilitate strand invasion in vitro, however its precise function at these later stages is unclear.
Ashton et al. BMC Molecular Biology 2013 14:9 doi:10.1186/1471-2199-14-9