The RuvA-RuvB complex in the presence of ATP renatures cruciform structure in supercoiled DNA with palindromic sequence, indicating that it may promote strand exchange reactions in homologous recombination. RuvAB is a helicase that mediates the Holliday junction migration by localized denaturation and reannealing. RuvA stimulates, in the presence of DNA, the weak ATPase activity of RuvB. Plays a role in recovery after DNA ADP-ribosylation. ATP + H2O = ADP + H(+) + phosphate Forms a complex with RuvB. Significantly reduced survival of cells expressing DNA ADP-ribosyl transferase (darT) mutant G49D. Belongs to the RuvA family.