title: The three-dimensional structure of proteasomes from Thermoplasma acidophilum as determined by electron microscopy using random conical tilting.
abstract: The three-dimensional structure of proteasomes from the archaebacterium Thermoplasma acidophilum has been determined to a resolution of approximately 2 nm from electron micrographs of negatively stained preparations using the method of 'random conical tilting'. The particles turn out to be essentially cylinder-shaped barrels, 15 nm long and 11 nm wide, enclosing a tripartite inner compartiment. An account is given of some of the present limitations which prevent to attain a higher resolution and possible ways to overcome these limitations are indicated.
authors.affiliation: Max-Planck-Institut für Biochemie, Martinsried, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Hegerl
authors.forename: G
authors.initials: G
authors.lastname: Pfeifer
authors.forename: G
authors.initials: G
authors.lastname: Pühler
authors.forename: B
authors.initials: B
authors.lastname: Dahlmann
authors.forename: W
authors.initials: W
authors.lastname: Baumeister
mesh_terms: D003546:Cysteine Endopeptidases / Q000737:chemistry* / Q000648:ultrastructure; D008854:Microscopy, Electron; D009097:Multienzyme Complexes / Q000737:chemistry* / Q000648:ultrastructure; D046988:Proteasome Endopeptidase Complex; D011487:Protein Conformation; D013822:Thermoplasma / Q000201:enzymology*
chemical_list: D009097:Multienzyme Complexes; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex