Related Experiment Video
Updated: Jul 15, 2026

Real-time Observation of the DNA Strand Exchange Reaction Mediated by Rad51
Published on: February 13, 2019
Swi3p controls SWI/SNF assembly and ATP-dependent H2A-H2B displacement
Xiaofang Yang1, Roser Zaurin, Miguel Beato
1Interdisciplinary Graduate Program, Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA.
Abstract:
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.
Related Concept Videos
Nucleosome Remodeling
Nucleosome remodeling complex
Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes...
DNA Helicases
The Spindle Assembly Checkpoint
Many proteins function together to control the spindle assembly checkpoint. Mutations affecting these proteins may allow cells to proceed into anaphase prematurely, resulting in the...
Restarting Stalled Replication Forks
Single-Strand DNA Binding Proteins
Protein Complex Assembly
Many viruses self-assemble into a fully functional unit using the infected host cell to...

