title: Structure of Sindbis virus core protein reveals a chymotrypsin-like serine proteinase and the organization of the virion.
abstract: Sindbis virus consists of a nucleocapsid core surrounded by a lipid membrane through which penetrate 80 glycoprotein trimers. The structure of the core protein comprising the coat surrounding the genomic RNA has been determined. The polypeptide fold from residue 114 to residue 264 is homologous to that of chymotrypsin-like serine proteinases with catalytic residues His 141, Asp 163 and Ser 215 of the core protein positioned as in other serine proteinases. The C-terminal tryptophan remains in the P1 substrate site subsequent to the autocatalytic cis cleavage of the capsid protein, thus rendering the proteinase inactive. Model building of the Sindbis core protein dimer shows that the nucleocapsid is likely to have T = 4 quasisymmetry.
authors.affiliation: Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907.
authors.forename: H K
authors.initials: HK
authors.lastname: Choi
authors.forename: L
authors.initials: L
authors.lastname: Tong
authors.forename: W
authors.initials: W
authors.lastname: Minor
authors.forename: P
authors.initials: P
authors.lastname: Dumas
authors.forename: U
authors.initials: U
authors.lastname: Boege
authors.forename: M G
authors.initials: MG
authors.lastname: Rossmann
authors.forename: G
authors.initials: G
authors.lastname: Wengler
mesh_terms: D000595:Amino Acid Sequence; D005075:Biological Evolution; D002918:Chymotrypsin / Q000737:chemistry; D008969:Molecular Sequence Data; D015394:Molecular Structure; D012697:Serine Endopeptidases / Q000737:chemistry*; D012845:Sindbis Virus / Q000737:chemistry*; D014758:Viral Core Proteins / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D014758:Viral Core Proteins; D012697:Serine Endopeptidases; D002918:Chymotrypsin