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. 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 (By similarity). Required for maintaining open chromatin and pluripotency in embryonic stem cells (PubMed:19587682). Is also associated with histone deacetylase (HDAC) activity (PubMed:12890497). ATP + H2O = ADP + H(+) + phosphate Component of the SAGA complex (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 (By similarity). Interacts with BCLAF1, NCoR, SRP20 and SAFB. Is released into the cytoplasm when cells enter mitosis and is reincorporated into chromatin during telophase-cytokinesis (PubMed:7739555). Abundance is higher in cells representing early stages of the B-lymphoid lineage such as pre-B and B-cells, than in cells representing mature plasmacytes or other cell lineages such as fibroblasts. The 2 chromodomains are involved in the binding to the histone H3 methyllysine at position 4 (H3K4me3). Belongs to the SNF2/RAD54 helicase family.