2og3
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structure of the rna binding domain of n protein from SARS coronavirus in cubic crystal form
OverviewOverview
Conserved among all coronaviruses are four structural proteins: the matrix, (M), small envelope (E), and spike (S) proteins that are embedded in the, viral membrane and the nucleocapsid phosphoprotein (N), which exists in a, ribonucleoprotein complex in the lumen. The N-terminal domain of, coronaviral N proteins (N-NTD) provides a scaffold for RNA binding, while, the C-terminal domain (N-CTD) mainly acts as oligomerization modules, during assembly. The C terminus of the N protein anchors it to the viral, membrane by associating with M protein. We characterized the structures of, N-NTD from severe acute respiratory syndrome coronavirus (SARS-CoV) in two, crystal forms, at 1.17 A (monoclinic) and at 1.85 A (cubic), respectively, resolved by molecular replacement using the homologous avian infectious, bronchitis virus (IBV) structure. Flexible loops in the solution structure, of SARS-CoV N-NTD are now shown to be well ordered around the beta-sheet, core. The functionally important positively charged beta-hairpin protrudes, out of the core, is oriented similarly to that in the IBV N-NTD, and is, involved in crystal packing in the monoclinic form. In the cubic form, the, monomers form trimeric units that stack in a helical array. Comparison of, crystal packing of SARS-CoV and IBV N-NTDs suggests a common mode of RNA, recognition, but they probably associate differently in vivo during the, formation of the ribonucleoprotein complex. Electrostatic potential, distribution on the surface of homology models of related coronaviral, N-NTDs suggests that they use different modes of both RNA recognition and, oligomeric assembly, perhaps explaining why their nucleocapsids have, different morphologies.
About this StructureAbout this Structure
2OG3 is a Single protein structure of sequence from Sars coronavirus. Full crystallographic information is available from OCA.
ReferenceReference
Ribonucleocapsid Formation of Severe Acute Respiratory Syndrome Coronavirus through Molecular Action of the N-Terminal Domain of N Protein., Saikatendu KS, Joseph JS, Subramanian V, Neuman BW, Buchmeier MJ, Stevens RC, Kuhn P, J Virol. 2007 Apr;81(8):3913-21. Epub 2007 Jan 17. PMID:17229691
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