Functions in error-free postreplication DNA repair or DNA-damage tolerance (DTT) pathway (PubMed:18310306, PubMed:21549648). Required for homologous recombination (HR) induced by DNA double-strand break (DSB) in somatic cells (PubMed:18310306). Required for damage-induced DNA repair, independently of MUS81 and RECQL4A. Plays a role in synthesis-dependent strand annealing (SDSA) but not in single-strand annealing (SSA) (PubMed:20971895). Possesses double-stranded DNA-dependent ATPase activity. Is able to regress replication forks with preference for forks with a leading strand gap. Is able to catalyze branch migration of Holliday junctions and is unaffected by protein blockades (PubMed:27458713). Belongs to the SNF2/RAD54 helicase family. RAD16 subfamily.