Helicase which acts in nucleosome-remodeling by catalyzing ATP-dependent nucleosome mobilization (PubMed:18250149). Involved in regulating transcription (PubMed:9836641, PubMed:18250149). Plays a vital role in development (PubMed:9836641). Binds to a portion of Hunchback (HB) protein that is critical for repression of bithorax complex (BXC) genes (PubMed:9836641). May also function in polycomb group (PcG) repression of Hox genes (PubMed:9836641). May also act as part of the nucleosome remodeling and deacetylase complex (the NuRD complex) which participates in the remodeling of chromatin by deacetylating histones (PubMed:18250149). ATP + H2O = ADP + H(+) + phosphate ATPase activity is stimulated by binding to either DNA or nucleosomes. Interacts with the NuRD complex member HDAC1/Rpd3. During embryogenesis, detected in nuclei before and after their migration to the membrane of the preblastoderm embryo (PubMed:18250149). Expression is diffuse in mitotic nuclei and is still detectable in nuclei at postgastrulation (PubMed:18250149). In polytene chromosomes of third instar larvae, weakly expressed at the chromocenter and fourth chromosome (PubMed:18250149). Expressed in embryos, with levels peaking around 6 to 9 hours after egg deposition, and then sharply decreases becoming undetectable at the first larval stage (at protein level) (PubMed:18250149). Reappears at the pupal stage when it is weakly expressed (at protein level) (PubMed:18250149). Strongly expressed in adult females but expression is low to absent in adult males (at protein level) (PubMed:18250149). Belongs to the SNF2/RAD54 helicase family.