title: Nucleosome remodeling by the human SWI/SNF complex requires transient global disruption of histone-DNA interactions.
abstract: We utilized a site-specific cross-linking technique to investigate the mechanism of nucleosome remodeling by hSWI/SNF. We found that a single cross-link between H2B and DNA virtually eliminates the accumulation of stably remodeled species as measured by restriction enzyme accessibility assays. However, cross-linking the histone octamer to nucleosomal DNA does not inhibit remodeling as monitored by DNase I digestion assays. Importantly, we found that the restriction enzyme-accessible species can be efficiently cross-linked after remodeling and that the accessible state does not require continued ATP hydrolysis. These results imply that the generation of stable remodeled states requires at least transient disruption of histone-DNA interactions throughout the nucleosome, while hSWI/SNF-catalyzed disruption of just local histone-DNA interactions yields less-stable remodeled states that still display an altered DNase I cleavage pattern. The implications of these results for models of the mechanism of SWI/SNF-catalyzed nucleosome remodeling are discussed.
authors: Department of Biochemistry and Biophysics, University of Rochester Medical Center, Rochester, New York 14642, USA.
authors: Sayura
authors: S
authors: Aoyagi
authors: Geeta
authors: G
authors: Narlikar
authors: Chunyang
authors: C
authors: Zheng
authors: Saïd
authors: S
authors: Sif
authors: Robert E
authors: RE
authors: Kingston
authors: Jeffrey J
authors: JJ
authors: Hayes
mesh_terms: D000818:Animals; D001665:Binding Sites; D003432:Cross-Linking Reagents; D004247:DNA / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D003850:Deoxyribonuclease I; D006657:Histones / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D046911:Macromolecular Substances; D008954:Models, Biological; D009707:Nucleosomes / Q000378:metabolism*; D014981:Xenopus
chemical_list: D003432:Cross-Linking Reagents; D004268:DNA-Binding Proteins; D006657:Histones; D046911:Macromolecular Substances; D009707:Nucleosomes; D004247:DNA; D003850:Deoxyribonuclease I