title: Structure of the 26S proteasome from Schizosaccharomyces pombe at subnanometer resolution.
abstract: The structure of the 26S proteasome from Schizosaccharomyces pombe has been determined to a resolution of 9.1 Å by cryoelectron microscopy and single particle analysis. In addition, chemical cross-linking in conjunction with mass spectrometry has been used to identify numerous residue pairs in close proximity to each other, providing an array of spatial restraints. Taken together these data clarify the topology of the AAA-ATPase module in the 19S regulatory particle and its spatial relationship to the α-ring of the 20S core particle. Image classification and variance analysis reveal a belt of high "activity" surrounding the AAA-ATPase module which is tentatively assigned to the reversible association of proteasome interacting proteins and the conformational heterogeneity among the particles. An integrated model is presented which sheds light on the early steps of protein degradation by the 26S complex.
authors.affiliation: Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Bohn
authors.forename: Florian
authors.initials: F
authors.lastname: Beck
authors.forename: Eri
authors.initials: E
authors.lastname: Sakata
authors.forename: Thomas
authors.initials: T
authors.lastname: Walzthoeni
authors.forename: Martin
authors.initials: M
authors.lastname: Beck
authors.forename: Ruedi
authors.initials: R
authors.lastname: Aebersold
authors.forename: Friedrich
authors.initials: F
authors.lastname: Förster
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Baumeister
authors.forename: Stephan
authors.initials: S
authors.lastname: Nickell
mesh_terms: D020285:Cryoelectron Microscopy / Q000379:methods; D013058:Mass Spectrometry / Q000379:methods; D056004:Molecular Dynamics Simulation; D046988:Proteasome Endopeptidase Complex / Q000737:chemistry*; D011487:Protein Conformation; D011506:Proteins / Q000378:metabolism; D012568:Schizosaccharomyces / Q000737:chemistry*
chemical_list: D011506:Proteins; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease; C119011:26S proteasome non-ATPase regulatory subunit 13