title: Structural analyses of the chromatin remodelling enzymes INO80-C and SWR-C.
abstract: INO80-C and SWR-C are conserved members of a subfamily of ATP-dependent chromatin remodelling enzymes that function in transcription and genome-maintenance pathways. A crucial role for these enzymes is to control chromosomal distribution of the H2A.Z histone variant. Here we use electron microscopy (EM) and two-dimensional class averaging to demonstrate that these remodelling enzymes have similar overall architectures. Each enzyme is characterized by a dynamic 'tail' domain and a compact 'head' that contains Rvb1/Rvb2 subunits organized as hexameric rings. EM class averages and mass spectrometry support the existence of single heterohexameric rings in both SWR-C and INO80-C. EM studies define the position of the Arp8/Arp4/Act1 module within INO80-C, and we find that this module enhances nucleosome-binding affinity but is largely dispensable for remodelling activities. In contrast, the Ies6/Arp5 module is essential for INO80-C remodelling, and furthermore this module controls conformational changes that may couple nucleosome binding to remodelling.
authors.affiliation: Program in Molecular Medicine, University of Massachusetts Medical School, 373 Plantation Street, Worcester, Maasachusetts 01605, USA.
authors.forename: Shinya
authors.initials: S
authors.lastname: Watanabe
authors.affiliation: 1] Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA [2] Howard Hughes Medical Institute, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA.
authors.forename: Dongyan
authors.initials: D
authors.lastname: Tan
authors.affiliation: Stowers Institute for Medical Research, 1000 E 50th Street, Kansas, Missouri 64110, USA.
authors.forename: Mahadevan
authors.initials: M
authors.lastname: Lakshminarasimhan
authors.affiliation: 1] Stowers Institute for Medical Research, 1000 E 50th Street, Kansas, Missouri 64110, USA [2] Departments of Pathology and Laboratory Medicine, University of Kansas Medical Center, Kansas, Kansas 66160, USA.
authors.forename: Michael P
authors.identifier: 0000000175682585
authors.initials: MP
authors.lastname: Washburn
authors.affiliation: Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA.
authors.forename: Eun-Jin Erica
authors.initials: EJ
authors.lastname: Hong
authors.affiliation: 1] Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA [2] Howard Hughes Medical Institute, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Walz
authors.affiliation: Program in Molecular Medicine, University of Massachusetts Medical School, 373 Plantation Street, Worcester, Maasachusetts 01605, USA.
authors.forename: Craig L
authors.initials: CL
authors.lastname: Peterson
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D042002:Chromatin Assembly and Disassembly / Q000502:physiology*; D015966:Gene Expression Regulation, Fungal / Q000502:physiology*; D007091:Image Processing, Computer-Assisted; D008854:Microscopy, Electron; D057054:Molecular Imaging; D011487:Protein Conformation; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: C483404:INO80 complex, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D000251:Adenosine Triphosphatases