ATPase which is preferentially stimulated by single-stranded DNA and is involved in homologous recombination repair (HRR). Has a DNA-binding activity which is independent of its ATPase activity. Interacts with ZSWIM7; they form a functional complex involved in homologous recombination repair and stabilize each other. Interacts with RAD51, RAD51B, RAD51C, RAD51D and XRCC3; involved in homologous recombination repair.