Structure of Sindbis virus core protein reveals a chymotrypsin-like serine proteinase and the organization of the virion

• Published in: Nature (London) 1991-11, Vol.354 (6348), p.37-43
• Main Authors: Choi, Hok-Kin, Tong, Liang, Minor, Wladek, Dumas, Philippe, Boege, Ulrike, Rossmann, Michael G, Wengler, Gerd
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Biological and medical sciences; Biological Evolution; chymotrypsin; Chymotrypsin - chemistry; core protein; crystal structure; Crystalline structure; Fundamental and applied biological sciences. Psychology; Genetics; Humanities and Social Sciences; Molecular biophysics; Molecular Sequence Data; Molecular Structure; multidisciplinary; nucleocapsids; Proteins; Ribonucleic acid; RNA; Science; Science (multidisciplinary); Serine Endopeptidases - chemistry; serine proteinase; Sindbis Virus - chemistry; Structure in molecular biology; Viral Core Proteins - chemistry; Viruses; X-Ray Diffraction
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/354037a0

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 poly-peptide 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 tryp-tophan remains in the P 1 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.