title: Structural studies of the scrapie prion protein by electron crystallography.
abstract: Because the insolubility of the scrapie prion protein (PrP(Sc)) has frustrated structural studies by x-ray crystallography or NMR spectroscopy, we used electron crystallography to characterize the structure of two infectious variants of the prion protein. Isomorphous two-dimensional crystals of the N-terminally truncated PrP(Sc) (PrP 27-30) and a miniprion (PrP(Sc)106) were identified by negative stain electron microscopy. Image processing allowed the extraction of limited structural information to 7 A resolution. By comparing projection maps of PrP 27-30 and PrP(Sc)106, we visualized the 36-residue internal deletion of the miniprion and localized the N-linked sugars. The dimensions of the monomer and the locations of the deleted segment and sugars were used as constraints in the construction of models for PrP(Sc). Only models featuring parallel beta-helices as the key element could satisfy the constraints. These low-resolution projection maps and models have implications for understanding prion propagation and the pathogenesis of neurodegeneration.
authors.affiliation: Department of Neurology, University of California, San Francisco, CA 94143, USA.
authors.forename: Holger
authors.initials: H
authors.lastname: Wille
authors.forename: Melissa D
authors.initials: MD
authors.lastname: Michelitsch
authors.forename: Vincent
authors.initials: V
authors.lastname: Guenebaut
authors.forename: Surachai
authors.initials: S
authors.lastname: Supattapone
authors.forename: Ana
authors.initials: A
authors.lastname: Serban
authors.forename: Fred E
authors.initials: FE
authors.lastname: Cohen
authors.forename: David A
authors.initials: DA
authors.lastname: Agard
authors.forename: Stanley B
authors.initials: SB
authors.lastname: Prusiner
mesh_terms: D000818:Animals; D002256:Carbonic Anhydrases / Q000737:chemistry; D003460:Crystallization; D006031:Glycosylation; D007091:Image Processing, Computer-Assisted; D017020:Methanosarcina / Q000201:enzymology; D008854:Microscopy, Electron; D008958:Models, Molecular; D010446:Peptide Fragments / Q000737:chemistry / Q000648:ultrastructure; D018622:PrP 27-30 Protein / Q000737:chemistry / Q000648:ultrastructure; D018620:PrPSc Proteins / Q000737:chemistry* / Q000648:ultrastructure*; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D012608:Scrapie / Q000378:metabolism*; D012995:Solubility
chemical_list: D010446:Peptide Fragments; D018620:PrPSc Proteins; D018622:PrP 27-30 Protein; D002256:Carbonic Anhydrases