Abstract
Holliday junction is a universal intermediate in DNA homologous recombination. In prokaryotes, RuvA, RuvB and RuvC proteins play crucial roles in the late stage of the recombination through mediating ATP-dependent branch migration and resolution of Holliday junction. The specific binding of the RuvA tetramer to the junction DNA allows RuvB to assemble on DNA as a hexameric ring. To clarify how Holliday junction is recognized by RuvA, we determined the crystal structure of the RuvA-Holliday junction complex. The structure reveals the recognition mechanism specific for the junction structure. It also disclosed the positive role of RuvA in rearranging base pairs at the junction center during branch migration.
