title: Nucleosome mobilization catalysed by the yeast SWI/SNF complex.
abstract: The generation of a local chromatin topology conducive to transcription is a key step in gene regulation. The yeast SWI/SNF complex is the founding member of a family of ATP-dependent remodelling activities capable of altering chromatin structure both in vitro and in vivo. Despite its importance, the pathway by which the SWI/SNF complex disrupts chromatin structure is unknown. Here we use a model system to demonstrate that the yeast SWI/SNF complex can reposition nucleosomes in an ATP-dependent reaction that favours attachment of the histone octamer to an acceptor site on the same molecule of DNA (in cis). We show that SWI/SNF-mediated displacement of the histone octamer is effectively blocked by a barrier introduced into the DNA, suggesting that this redistribution involves sliding or tracking of nucleosomes along DNA, and that it is achieved by a catalytic mechanism. We conclude that SWI/SNF catalyses the redistribution of nucleosomes along DNA in cis, which may represent a general mechanism by which ATP-dependent chromatin remodelling occurs.
authors.affiliation: Division of Gene Regulation, University of Dundee, UK.
authors.forename: I
authors.initials: I
authors.lastname: Whitehouse
authors.forename: A
authors.initials: A
authors.lastname: Flaus
authors.forename: B R
authors.initials: BR
authors.lastname: Cairns
authors.forename: M F
authors.initials: MF
authors.lastname: White
authors.forename: J L
authors.initials: JL
authors.lastname: Workman
authors.forename: T
authors.initials: T
authors.lastname: Owen-Hughes
mesh_terms: D002384:Catalysis; D002868:Chromosomal Proteins, Non-Histone; D004271:DNA, Fungal / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004926:Escherichia coli; D005656:Fungal Proteins / Q000378:metabolism*; D006367:HeLa Cells; D006657:Histones / Q000378:metabolism; D006801:Humans; D046911:Macromolecular Substances; D009690:Nucleic Acid Conformation; D009707:Nucleosomes / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D015003:Yeasts
chemical_list: C116140:ARP9 protein, S cerevisiae; D002868:Chromosomal Proteins, Non-Histone; D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D006657:Histones; D046911:Macromolecular Substances; D009707:Nucleosomes; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins