NR ABOF
AU Bousset,L.; Belrhali,H.; Janin,J.; Melki,R.; Morera,S.
TI Structure of the globular region of the prion protein Ure2 from the yeast Saccharomyces cerevisiae
QU Structure (Cambridge, Mass. : 2001) 2001 Jan 10; 9(1): 39-46
PT journal article
AB BACKGROUND: The [URE3] non-Mendelian element of the yeast S. cerevisiae is due to the propagation of a transmissible form of the protein Ure2. The infectivity of Ure2p is thought to originate from a conformational change of the normal form of the prion protein. This conformational change generates a form of Ure2p that assembles into amyloid fibrils. Hence, knowledge of the three-dimensional structure of prion proteins such as Ure2p should help in understanding the mechanism of amyloid formation associated with a number of neurodegenerative diseases. RESULTS: Here we report the three-dimensional crystal structure of the globular region of Ure2p (residues 95-354), also called the functional region, solved at 2.5 A resolution by the MAD method. The structure of Ure2p 95-354 shows a two-domain protein forming a globular dimer. The N-terminal domain is composed of a central 4 strand beta sheet flanked by four alpha helices, two on each side. In contrast, the C-terminal domain is entirely alpha-helical. The fold of Ure2p 95-354 resembles that of the beta class glutathione S-transferases (GST), in line with a weak similarity in the amino acid sequence that exists between these proteins. Ure2p dimerizes as GST does and possesses a potential ligand binding site, although it lacks GST activity. CONCLUSIONS: The structure of the functional region of Ure2p is the first crystal structure of a prion protein. Structure comparisons between Ure2p 95-354 and GST identified a 32 amino acid residues cap region in Ure2p exposed to the solvent. The cap region is highly flexible and may interact with the N-terminal region of the partner subunit in the dimer. The implication of this interaction in the assembly of Ure2p into amyloid fibrils is discussed.
MH Amino Acid Sequence; Amyloid/chemistry; Binding Sites; Crystallography, X-Ray; Dimerization; Fungal Proteins/*chemistry; Glutathione Transferase/chemistry; Ligands; Models, Molecular; Molecular Sequence Data; Prions/*chemistry; Protein Conformation; Protein Structure, Secondary; Protein Structure, Tertiary; Saccharomyces cerevisiae/*chemistry; Sequence Homology, Amino Acid; Support, Non-U.S. Gov't
AD Laboratoire d'Enzymologie et Biochimie Structurales, CNRS, Avenue de la Terrasse, 91198 Gif-sur-Yvette, France.
SP englisch
PO USA