Background: Brahma (BRM) is the only catalytic subunit of the SVVI/SNF chromatin-remodeling complex of Drosophila melanogaster. The function of SWI/SNF in transcription has long been attributed to its ability to remodel nucleosomes, which requires the ATPase activity of BRM. However, recent studies have provided evidence for a non-catalytic function of BRM in the transcriptional regulation of a few specific genes.

Results: Here we have used RNA-seq and ChIP-seq to identify the BRM target genes in 52 cells, and we have used a catalytically inactive BRM mutant (K804R) that is unable to hydrolyze ATP to investigate the magnitude of the non-catalytic function of BRM in transcription regulation. We show that 49% of the BRM target genes in 52 cells are regulated through mechanisms that do not require BRM to have an ATPase activity. We also show that the catalytic and non-catalytic mechanisms of SVVI/SNF regulation operate on two subsets of genes that differ in promoter architecture and are linked to different biological processes.

Conclusions: This study shows that the non-catalytic role of SWI/SNF in transcription regulation is far more prevalent than previously anticipated and that the genes that are regulated by SVVI/SNF through ATPase-dependent and ATPase-independent mechanisms have specialized roles in different cellular and developmental processes.