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. ATP + H2O = ADP + H(+) + phosphate Homododecamer composed of two hexameric rings; when bound to DNA in the presence of ATP and magnesium. Forms a complex with RuvA (By similarity). Belongs to the RuvB family.