Rad52

What is the Rad52 protein? The Saccharomyces cerevisiae Rad52 protein is a key player in DNA doublestrand break repair and homologous recombination. It forms a heptameric ring, catalyses DNA annealing and mediates Rad51-catalysed strand invasion. RAD52 is the defining member of an epistasis group of genes involved in repair of ionizing radiationinduced DNA double-strand breaks. Double-strand break repair catalysed by this group of proteins is generally error-free, because genetic information at the double-strand break is restored from an intact copy elsewhere in the genome. Rad52 homologues have been identified in eukaryotic organisms ranging from yeast to humans, but they appear to be absent in some life forms, such as plants and invertebrates. Although Rad52 plays a prominent role in homologous recombination and DNA double-strand break repair in S. cerevisiae, it plays a more modest role in vertebrates, where additional proteins like BRCA2 have evolved to perform similar functions. Nevertheless, the biochemical activities of Rad52 proteins from different species are very similar.