Swi3p controls SWI/SNF assembly and ATP-dependent H2A-H2B displacement

UMMS Affiliation

Graduate School of Biomedical Sciences; Department of Cancer Biology; Program in Molecular Medicine

Publication Date


Document Type



Life Sciences | Medicine and Health Sciences


Yeast SWI/SNF is a multisubunit, 1.14-MDa ATP-dependent chromatin-remodeling enzyme required for transcription of a subset of inducible genes. Biochemical studies have demonstrated that SWI/SNF uses the energy from ATP hydrolysis to generate superhelical torsion, mobilize mononucleosomes, enhance the accessibility of nucleosomal DNA and remove H2A-H2B dimers from mononucleosomes. Here we describe the ATP-dependent activities of a SWI/SNF sub complex that is composed of only three subunits, Swi2p, Arp7p and Arp9p. Whereas this sub complex is fully functional in most remodeling assays, Swi2p-Arp7p-Arp9p is defective for ATP-dependent removal of H2A-H2B dimers. We identify the acidic N terminus of the Swi3p subunit as a novel H2A-H2B-binding domain required for ATP-dependent dimer loss. Our data indicate that H2A-H2B dimer loss is not an obligatory consequence of ATP-dependent DNA translocation, and furthermore they suggest that SWI/SNF is composed of at least four interdependent modules.

DOI of Published Version



Nat Struct Mol Biol. 2007 Jun;14(6):540-7. Epub 2007 May 13. Link to article on publisher's site

Journal/Book/Conference Title

Nature structural and molecular biology

Related Resources

Link to Article in PubMed

PubMed ID