title: Recombinant severe acute respiratory syndrome (SARS) coronavirus nucleocapsid protein forms a dimer through its C-terminal domain.
abstract: The causative agent of severe acute respiratory syndrome (SARS) is the SARS-associated coronavirus, SARS-CoV. The viral nucleocapsid (N) protein plays an essential role in viral RNA packaging. In this study, recombinant SARS-CoV N protein was shown to be dimeric by analytical ultracentrifugation, size exclusion chromatography coupled with light scattering, and chemical cross-linking. Dimeric N proteins self-associate into tetramers and higher molecular weight oligomers at high concentrations. The dimerization domain of N was mapped through studies of the oligomeric states of several truncated mutants. Although mutants consisting of residues 1-210 and 1-284 fold as monomers, constructs consisting of residues 211-422 and 285-422 efficiently form dimers. When in excess, the truncated construct 285-422 inhibits the homodimerization of full-length N protein by forming a heterodimer with the full-length N protein. These results suggest that the N protein oligomerization involves the C-terminal residues 285-422, and this region is a good target for mutagenic studies to disrupt N protein self-association and virion assembly.
authors.affiliation: Department of Biological Sciences and the Cancer Center, Purdue University, West Lafayette, Indiana 47907, USA.
authors.forename: I-Mei
authors.initials: IM
authors.lastname: Yu
authors.forename: Christin L T
authors.initials: CL
authors.lastname: Gustafson
authors.forename: Jianbo
authors.initials: J
authors.lastname: Diao
authors.forename: John W
authors.initials: JW
authors.lastname: Burgner
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Li
authors.forename: Jingqiang
authors.initials: J
authors.lastname: Zhang
authors.forename: Jue
authors.initials: J
authors.lastname: Chen
mesh_terms: D002845:Chromatography; D000086462:Coronavirus Nucleocapsid Proteins; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004277:DNA, Single-Stranded / Q000737:chemistry; D019281:Dimerization; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000378:metabolism; D008027:Light; D016296:Mutagenesis; D009154:Mutation; D009696:Nucleic Acids / Q000378:metabolism; D019590:Nucleocapsid Proteins / Q000737:chemistry* / Q000378:metabolism; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012313:RNA / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry*; D045473:Severe acute respiratory syndrome-related coronavirus / Q000378:metabolism*; D012542:Scattering, Radiation; D016622:Silver Staining; D014461:Ultracentrifugation
chemical_list: D000086462:Coronavirus Nucleocapsid Proteins; D003432:Cross-Linking Reagents; D004277:DNA, Single-Stranded; D009696:Nucleic Acids; D019590:Nucleocapsid Proteins; D011994:Recombinant Proteins; D012313:RNA