ATP-dependent 3'- to 5'-DNA helicase that could disrupt recombinogenic DNA intermediates and facilitate single strand annealing. Unwinds nicked and partial Holliday junctions in vitro. Anneals two single strands into a dsDNA molecule in vitro. ATP + H2O = ADP + H(+) + phosphate Belongs to the helicase family. UvrD subfamily.