ATP-dependent annealing helicase that binds selectively to fork DNA relative to ssDNA or dsDNA and catalyzes the rewinding of the stably unwound DNA. Rewinds single-stranded DNA bubbles that are stably bound by replication protein A (RPA). Acts throughout the genome to reanneal stably unwound DNA, performing the opposite reaction of many enzymes, such as helicases and polymerases, that unwind DNA. May play an important role in DNA damage response by acting at stalled replication forks. Interacts with RPA2; the interaction is direct and mediates the recruitment by the RPA complex of SMARCAL1 to sites of DNA damage. Recruited to damaged DNA regions. Ubiquitously expressed, with high levels in testis. DNA damage-regulated phosphorylation by kinases that may include ATM, ATR and PRKDC. The disease is caused by variants affecting the gene represented in this entry. Belongs to the SNF2/RAD54 helicase family. SMARCAL1 subfamily. Truncated N-terminus. SMARCAL1 mutation db