<p>In prokaryotes, RuvA, RuvB, and RuvC process the universal DNA intermediate of homologous recombination, termed Holliday junction. The tetrameric DNA helicase RuvA specifically binds to the Holliday junction and facilitates the isomerization of the junction from the stacked folded configuration to the square-planar structure [<cite idref="PUB00013198"/>]. In the RuvA tetramer, each subunit consists of three domains, I, II and III, where I and II form the major core that is responsible for Holliday junction binding and base pair rearrangements of Holliday junction executed at the crossover point, whereas domain III regulates branch migration through direct contact with RuvB.</p><p>This entry represents domain I of RuvA, which has an OB-fold structure. This domain forms the RuvA tetramer contacts [<cite idref="PUB00005222"/>].</p> DNA helicase, Holliday junction RuvA type, domain I, bacterial