2mxd
Solution structure of VPg of porcine sapovirus
Structural highlights
FunctionPOLG_PESV NTPase presumably plays a role in replication. Despite having similarities with helicases, does not seem to display any helicase activity (By similarity). Viral genome-linked protein is covalently linked to the 5'-end of the positive-strand, negative-strand genomic RNAs and subgenomic RNA. Acts as a genome-linked replication primer. May recruit ribosome to viral RNA thereby promoting viral proteins translation (By similarity). Protease-polymerase p70 processes the polyprotein: Pro-Pol is first released by autocleavage, then all other proteins are cleaved (By similarity). It is also an RNA-directed RNA polymerase which replicates genomic and antigenomic viral RNA by recognizing specific signals. Catalyzes the covalent attachment VPg with viral RNAs (By similarity). Capsid protein self assembles to form an icosahedral capsid with a T=3 symmetry, about 38 nm in diameter, and consisting of 180 capsid proteins. The capsid encapsulate the genomic RNA and VP2 proteins. Attaches virion to target cells, inducing endocytosis of the viral particle. Acidification of the endosome induces conformational change of capsid protein thereby injecting virus genomic RNA into host cytoplasm (By similarity). Publication Abstract from PubMedViral protein genome-linked (VPg) proteins play a critical role in the life cycle of vertebrate and plant positive-sense RNA viruses by acting as a protein primer for genome replication and as a protein cap for translation initiation. Here we report the solution structure of the porcine sapovirus VPg core (VPg(C)) determined by multi-dimensional NMR spectroscopy. The structure of VPg(C) is composed of three alpha-helices stabilized by several conserved hydrophobic residues that form a helical bundle core similar to that of feline calicivirus VPg. The putative nucleotide acceptor Tyr956 within the first helix of the core is completely exposed to solvent accessible surface to facilitate nucleotidylation by viral RNA polymerase. Comparison of VPg structures suggests that the surface for nucleotidylation site is highly conserved among the Caliciviridae family, whereas the backbone core structures are different. These structural features suggest that caliciviruses share common mechanisms of VPg-dependent viral replication and translation. Solution structure of the porcine sapovirus VPg core reveals a stable three-helical bundle with a conserved surface patch.,Hwang HJ, Min HJ, Yun H, Pelton JG, Wemmer DE, Cho KO, Kim JS, Lee CW Biochem Biophys Res Commun. 2015 Apr 17;459(4):610-6. doi:, 10.1016/j.bbrc.2015.02.156. Epub 2015 Mar 6. PMID:25753201[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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