The Rad52 SSAP superfamily and new insight into homologous recombination.

Rad52 is a highly conserved eukaryotic protein that can mediate the annealing of complementary DNA strands to initiate homologous recombination for the repair of double-strand breaks. Suspicions that at least some prokaryotic single-strand annealing proteins (SSAPs) are related to Rad52 have been discussed for more than two decades. Two recent cryo-EM structures now put the issue beyond doubt.