DNA helicase that possesses intrinsic ATP-dependent nucleosome-remodeling activity and is both required for DNA repair and heterochromatin organization. Promotes DNA end resection of double-strand breaks (DSBs) following DNA damage: probably acts by weakening histone DNA interactions in nucleosomes flanking DSBs. Required for the restoration of heterochromatin organization after replication. Acts at replication sites to facilitate the maintenance of heterochromatin by directing H3 and H4 histones deacetylation, H3 'Lys-9' trimethylation (H3K9me3) and restoration of silencing (By similarity). ATP + H2O = ADP + H(+) + phosphate Binds to DNA preferentially in the vicinity of transcriptional start sites. Interacts with MSH2 and TRIM28. Part of a complex composed of TRIM28, HDAC1, HDAC2 and EHMT2. Interacts with PCNA (By similarity). Colocalizes with PCNA at replication forks during S phase. Recruited to double-strand breaks (DSBs) sites of DNA damage (By similarity). Detected at low levels in fertilized and unfertilized eggs. Levels increased in two-cell embryos, decreased up to morula stage and were highest in blastocysts. Highly expressed in the inner cell mass of 3.5 day old blastocysts. Highly expressed in ectoderm and visceral endoderm at day 5.5. Detected throughout the brain and spinal cord at day 10 to 15. Detected in the basal layer of the epidermis after day 12.5, in particular on snout and distal on fore- and hindlimbs. Deficient mice have reduced viability and show growth retardation, skeletal dysplasia and impaired fertility. Belongs to the SNF2/RAD54 helicase family. Extended N-terminus. Extended N-terminus.