The function of the secondary site of RecA protein during DNA strand exchange

Characterization of the concerned action of the primary and secondary DNA binding site of RecA protein and an elucidation of the role of SSB protein in recombination reactions permitted the authors to clarify existing models of homologous recombination (see Fig. 4). In particular, Mazin and Kowalczykowski established that after DNA strand exchange the displaced strand tends to remain in the secondary DNA binding site of RecA filaments unless it is sequestered by SSB protein. By this activity, SSB protein prevents 'reversal' of DNA strand exchange.