SARS Coronavirus Unique Domain: Three-Domain Molecular Architecture in Solution and RNA Binding

JOURNAL OF MOLECULAR BIOLOGY

卷:400

Article

Johnson, Margaret A.¹  Chatterjee, Amarnath¹  Neuman, Benjamin W.^2,3  Wuethrich, Kurt^1,4,5 

[1] Scripps Res Inst, Dept Mol Biol, La Jolla, CA 92037 USA

[2] Scripps Res Inst, Dept Mol & Integrat Neurosci, La Jolla, CA 92037 USA

[3] Univ Reading, Sch Biol Sci, Reading RG6 6AJ, Berks, England

[4] Scripps Res Inst, Dept Chem, La Jolla, CA 92037 USA

[5] Scripps Res Inst, Skaggs Inst Chem Biol, La Jolla, CA 92037 USA

关键词: severe acute respiratory syndrome (SARS);    nonstructural protein 3 (nsp3);    RNA-binding proteins;    macrodomains;    frataxins;   

DOI  :  10.1016/j.jmb.2010.05.027

来源: Elsevier

【 摘 要 】

Nonstructural protein 3 of the severe acute respiratory syndrome (SARS) coronavirus includes a SARS-unique domain (SUD) consisting of three globular domains separated by short linker peptide segments. This work reports NMR structure determinations of the C-terminal domain (SUD-C) and a two-domain construct (SUD-MC) containing the middle domain (SUD-M) and the C-terminal domain, and NMR data on the conformational states of the N-terminal domain (SUD-N) and the SUD-NM two-domain construct. Both SUD-N and SUD-NM are monomeric and globular in solution; in SUD-NM, there is high mobility in the two-residue interdomain linking sequence, with no preferred relative orientation of the two domains. SUD-C adopts a frataxin like fold and has structural similarity to DNA-binding domains of DNA-modifying enzymes. The structures of both SUD-M (previously determined) and SUD-C (from the present study) are maintained in SUD-MC, where the two domains are flexibly linked. Gelshift experiments showed that both SUD-C and SUD-MC bind to single-stranded RNA and recognize purine bases more strongly than pyrimidine bases, whereby SUD-MC binds to a more restricted set of purine-containing RNA sequences than SUD-M. NMR chemical shift perturbation experiments with observations of N-15-labeled proteins further resulted in delineation of RNA binding sites (i.e., in SUD-M, a positively charged surface area with a pronounced cavity, and in SUD-C, several residues of an anti-parallel beta-sheet). Overall, the present data provide evidence for molecular mechanisms involving the concerted actions of SUD-M and SUD-C, which result in specific RNA binding that might be unique to the SUD and, thus, to the SARS coronavirus. (C) 2010 Elsevier Ltd. All rights reserved.

【 授权许可】

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