title: Crystal structure of the severe acute respiratory syndrome (SARS) coronavirus nucleocapsid protein dimerization domain reveals evolutionary linkage between corona- and arteriviridae.
abstract: The causative agent of severe acute respiratory syndrome (SARS) is the SARS-associated coronavirus, SARS-CoV. The nucleocapsid (N) protein plays an essential role in SARS-CoV genome packaging and virion assembly. We have previously shown that SARS-CoV N protein forms a dimer in solution through its C-terminal domain. In this study, the crystal structure of the dimerization domain, consisting of residues 270-370, is determined to 1.75A resolution. The structure shows a dimer with extensive interactions between the two subunits, suggesting that the dimeric form of the N protein is the functional unit in vivo. Although lacking significant sequence similarity, the dimerization domain of SARS-CoV N protein has a fold similar to that of the nucleocapsid protein of the porcine reproductive and respiratory syndrome virus. This finding provides structural evidence of the evolutionary link between Coronaviridae and Arteriviridae, suggesting that the N proteins of both viruses have a common origin.
authors.affiliation: Department of Biological Sciences and the Cancer Center, Purdue University, West Lafayette, Indiana 47907.
authors.forename: I-Mei
authors.initials: IM
authors.lastname: Yu
authors.affiliation: Department of Biological Sciences and the Cancer Center, Purdue University, West Lafayette, Indiana 47907.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Oldham
authors.affiliation: State Key Laboratory for Biocontrol, Zhongshan University, Guangzhou 510275, China.
authors.forename: Jingqiang
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Biological Sciences and the Cancer Center, Purdue University, West Lafayette, Indiana 47907. Electronic address: chenjue@purdue.edu.
authors.forename: Jue
authors.initials: J
authors.lastname: Chen
mesh_terms: D000595:Amino Acid Sequence; D028382:Arteriviridae / Q000235:genetics*; D000086462:Coronavirus Nucleocapsid Proteins; D018360:Crystallography, X-Ray; D019281:Dimerization; D019143:Evolution, Molecular; D008969:Molecular Sequence Data; D019590:Nucleocapsid Proteins / Q000737:chemistry*; D011485:Protein Binding; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D045473:Severe acute respiratory syndrome-related coronavirus / Q000235:genetics* / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid
chemical_list: D000086462:Coronavirus Nucleocapsid Proteins; D019590:Nucleocapsid Proteins