Practice question

Repositioning nucleosomes for regulated transcription demands mechanical force breaking 14 histone-DNA contacts. ATP-dependent chromatin remodelers couple ATP hydrolysis to translocate DNA around octamer. SWI/SNF family member containing SWI2/SNF2 ATPase domain hydrolyzes ATP sliding and evicting nucleosomes at promoters and enhancers, generating nucleosome depleted regions permitting preinitiation complex assembly. HAT and HDAC add or remove acetyl groups modulating charge not movement via ATP. DNMT methylates cytosine without remodeling. SWI/SNF mutations frequent in human cancers demonstrating tumor suppressor role maintaining accessibility. Thus ATP remodeling assigned to SWI/SNF complex specifically.