Practice question

ATP-dependent remodeling complexes reorganize chromatin by mobilizing nucleosomes without covalent modification. SWI/SNF family members contain Brg1 or Brm ATPase subunits that translocate DNA relative to octamer, peeling off contacts at entry site and propagating bulge around particle to shift position along duplex. Sliding exposes previously occluded transcription factor binding sites, facilitates activator binding and promoter clearance. Unlike ISWI which spaces nucleosomes regularly, SWI/SNF generates disordered arrays and ejects octamers at high density, acting as transcriptional co-activator at inducible genes requiring rapid access during development and stress response.