DNA-dependent ATPase component of the Fanconi anemia (FA) core complex (By similarity). Required for the normal activation of the FA pathway, leading to monoubiquitination of the FANCI-FANCD2 complex in response to DNA damage, cellular resistance to DNA cross-linking drugs, and prevention of chromosomal breakage (PubMed:16116434, PubMed:19465393). In complex with CENPS and CENPX, binds double-stranded DNA (dsDNA), fork-structured DNA (fsDNA) and Holliday junction substrates (By similarity). Its ATP-dependent DNA branch migration activity can process branched DNA structures such as a movable replication fork (By similarity). This activity is strongly stimulated in the presence of CENPS and CENPX (By similarity). In complex with FAAP24, efficiently binds to single-strand DNA (ssDNA), splayed-arm DNA, and 3'-flap substrates (By similarity). In vitro, on its own, strongly binds ssDNA oligomers and weakly fsDNA, but does not bind to dsDNA (By similarity).