ATP-dependent chromatin-remodeling factor which functions as substrate recognition component of the transcription regulatory histone acetylation (HAT) complex SAGA. Regulates polymerase II transcription. Also required for efficient transcription by RNA polymerase I, and more specifically the polymerase I transcription termination step. Regulates negatively DNA replication. Not only involved in transcription-related chromatin-remodeling, but also required to maintain a specific chromatin configuration across the genome. Is also associated with histone deacetylase (HDAC) activity (By similarity). Required for the bridging of SNF2, the FACT complex, the PAF complex as well as the U2 snRNP complex to H3K4me3. Functions to modulate the efficiency of pre-mRNA splicing in part through physical bridging of spliceosomal components to H3K4me3 (PubMed:18042460, PubMed:28866611). Required for maintaining open chromatin and pluripotency in embryonic stem cells (By similarity). ATP + H2O = ADP + H(+) + phosphate Component of the SAGA complex (By similarity). Interacts with BCLAF1, NCoR, SRP20 and SAFB (By similarity). Specifically interacts with methylated H3K4me2 and H3K4me3. Interacts with the FACT complex, the PAF complex and the U2 snRNP. Interacts directly with PAF1, SFA3A1, SFA3A2, SFA3A3, SNF2 and SSRP1. Is released into the cytoplasm when cells enter mitosis and is reincorporated into chromatin during telophase-cytokinesis. Expressed in many tissues including in the brain, where the highest level of expression is found in the cerebellum and basal ganglia. The 2 chromodomains are involved in the binding to the histone H3 methyllysine at position 4 (H3K4me3). The disease is caused by variants affecting the gene represented in this entry. Belongs to the SNF2/RAD54 helicase family.