Energy-transducing component of the chromatin-remodeling complexes NURF (nucleosome-remodeling factor), ACF (ATP-utilizing chromatin assembly and remodeling factor), and CHRAC (chromatin accessibility complex) (PubMed:10856248, PubMed:11447119). NURF catalyzes ATP-dependent nucleosome sliding and facilitates transcription of chromatin. It is required for homeotic gene expression, proper larval blood cell development, normal male X chromosome morphology, ecdysteroid signaling and metamorphosis (PubMed:12502740, PubMed:16264191, PubMed:8521501, PubMed:8521502). Component of the NURF complex composed of Caf1-55, E(bx), Nurf-38 and Iswi (PubMed:8521502). Component of the chromatin accessibility complex (CHRAC), composed of Chrac-14, Chrac-16, Acf and Iswi (PubMed:10856248, PubMed:11447119). Interacts directly with Chrac-14 and this interaction is further stabilized by associated Chrac-16 (PubMed:10856248). Present throughout embryonic, larval and pupal development and in female adults. Present at low levels in adult males (at protein level). Belongs to the SNF2/RAD54 helicase family. ISWI subfamily.