5vi7
Crystal structure of the Zika virus NS3 helicase
Structural highlights
FunctionPOLG_ZIKV Protein C: Encapsulates the genomic RNA.[UniProtKB:P17763] prM: Acts as a chaperone for envelope protein E during intracellular virion assembly by masking and inactivating envelope protein E fusion peptide. prM is matured in the last step of virion assembly, presumably to avoid catastrophic activation of the viral fusion peptide induced by the acidic pH of the trans-Golgi network. After cleavage by host furin, the pr peptide is released in the extracellular medium and small envelope protein M and envelope protein E homodimers are dissociated.[UniProtKB:P17763] Envelope protein E: Binding to host cell surface receptor is followed by virus internalization through clathrin-mediated endocytosis. Envelope protein E is subsequently involved in membrane fusion between virion and host late endosomes. Synthesized as a homodimer with prM which acts as a chaperone for envelope protein E. After cleavage of prM, envelope protein E dissociate from small envelope protein M and homodimerizes.[UniProtKB:P17763] Non-structural protein 1: Involved in virus replication and regulation of the innate immune response.[UniProtKB:P17763] Non-structural protein 2A: May be involved viral RNA replication and capsid assembly.[UniProtKB:P09732] Non-structural protein 4A: Induces host endoplasmic reticulum membrane rearrangements leading to the formation of virus-induced membranous vesicles hosting the dsRNA and polymerase, functioning as a replication complex. NS4A might also regulate the ATPase activity of the helicase region of Serine protease NS3 chain.[UniProtKB:P17763] Peptide 2k: Functions as a signal peptide for NS4B and is required for the interferon antagonism activity of the latter.[UniProtKB:P17763] Non-structural protein 4B: Inhibits interferon (IFN)-induced host STAT1 phosphorylation and nuclear translocation, thereby preventing the establishment of cellular antiviral state by blocking the IFN-alpha/beta pathway.[UniProtKB:P17763] Publication Abstract from PubMedTwo nonstructural proteins encoded by Zika virus strain MR766 RNA, a methyltransferase and a helicase, were crystallized and their structures were solved and refined at 2.10 and 2.01 A resolution, respectively. The NS5 methyltransferase contains a bound S-adenosyl-L-methionine (SAM) co-substrate. The NS3 helicase is in the apo form. Comparison with published crystal structures of the helicase in the apo, nucleotide-bound and single-stranded RNA (ssRNA)-bound states suggests that binding of ssRNA to the helicase may occur through conformational selection rather than induced fit. Crystal structures of the methyltransferase and helicase from the ZIKA 1947 MR766 Uganda strain.,Bukrejewska M, Derewenda U, Radwanska M, Engel DA, Derewenda ZS Acta Crystallogr D Struct Biol. 2017 Sep 1;73(Pt 9):767-774. doi:, 10.1107/S2059798317010737. Epub 2017 Aug 15. PMID:28876240[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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