This superfamily includes proteins related to Rad52. The human Rad52 protein forms a heptameric ring that catalyzes homologous pairing, the essential step of homologous recombination which involves searching for and pairing the homologous regions between single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA). The RecA protein plays a key role in prokaryotic recombination by promoting the pairing of two DNA molecules at homologous regions. In eukaryotes, homologs of RecA have been identified in many organisms, ranging from yeast to human, including Rad51. There are also ssDNA-annealing proteins that lack sequence homology to the RecA protein that also play essential roles in promoting the homologous pairing reaction, such as Rad52.

Rad52 protein is a recombination enzyme conserved among eukaryotic organisms that plays two distinct roles in homologous pairing. On one side it functions in the initial pairing steps of the Rad51-independent recombination processes but is also serves as a mediator protein in the Rad51-dependent recombination reaction, where it is proposed to facilitate the loading of Rad51 onto the recombination site PMID:12191481.