In the yeast, Saccharomyes cerevisiae, the Rad52 gene is important for
both mitotic and meiotic recombination. Homologs of the Rad52 gene ha
ve been identified in several eukaryotic organisms, ranging from yeast
to man. As reported here, human Rad52 protein binds to both single- a
nd double-stranded DNA; and acting on a pair of single-stranded and pa
rtially duplex substrates it promotes annealing of complementary stran
ds of DNA, which is followed by branch migration.