3l6p

Structural highlights

Function

POLG_DEN1W Capsid protein C self-assembles to form an icosahedral capsid about 30 nm in diameter. The capsid encapsulates the genomic RNA (By similarity). 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 (By similarity). 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 (By similarity). Non-structural protein 1 is involved in virus replication and regulation of the innate immune response. Soluble and membrane-associated NS1 may activate human complement and induce host vascular leakage. This effect might explain the clinical manifestations of dengue hemorrhagic fever and dengue shock syndrome (By similarity). Non-structural protein 2A may be involved viral RNA replication and capsid assembly (Potential). Non-structural protein 2B is a required cofactor for the serine protease function of NS3 (By similarity). Serine protease NS3 displays three enzymatic activities: serine protease, NTPase and RNA helicase. NS3 serine protease, in association with NS2B, performs its autocleavage and cleaves the polyprotein at dibasic sites in the cytoplasm: C-prM, NS2A-NS2B, NS2B-NS3, NS3-NS4A, NS4A-2K and NS4B-NS5. NS3 RNA helicase binds RNA and unwinds dsRNA in the 3' to 5' direction (By similarity). 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 NS3 helicase (By similarity). Peptide 2k functions as a signal peptide for NS4B and is required for the interferon antagonism activity of the latter (By similarity). 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 (By similarity). RNA-directed RNA polymerase NS5 replicates the viral (+) and (-) genome, and performs the capping of genomes in the cytoplasm. NS5 methylates viral RNA cap at guanine N-7 and ribose 2'-O positions. Besides its role in genome replication, also prevents the establishment of cellular antiviral state by blocking the interferon-alpha/beta (IFN-alpha/beta) signaling pathway. Inhibits host TYK2 and STAT2 phosphorylation, thereby preventing activation of JAK-STAT signaling pathway (By similarity).POLG_DEN1S Protein C: Plays a role in virus budding by binding to membrane and gathering the viral RNA into a nucleocapsid that forms the core of a mature virus particle. During virus entry, may induce genome penetration in host cytoplasm after hemifusion induced by surface proteins. Can migrate tot cell nucleus where it modulates host functions.[UniProtKB:P17763] Peptide pr: Prevents premature fusion activity of envelope proteins in trans Golgi by binding to envelope protein E at pH6.0. After virion release in extracellular space gets dissociated from E dimers.[UniProtKB:P17763] Protein prM: Acts as a chaperone for envelope protein E during intracellular virion assembly by masking and inactivating envelope protein E fusion peptide. prM is the only viral peptide matured by host furin in the trans-Golgi network. Presumably to avoid catastrophic activation of the viral fusion activity in acidic GolGi compartment prior to virion release. prM-E cleavage is ineficient, and many virions are only partially matured. These uncleaved prM would play a role in immune evasion.[UniProtKB:P17763] Small envelope protein M: May play a role in virus budding. Exerts cytotoxic effects by activating a mitochondrial apoptotic pathway through M extodomain. May display a viroporin activity.[UniProtKB:P17763] Envelope protein E: Binds to host cell surface receptor and mediates fusion between viral and cellular membranes. Envelope protein is synthesized in the endoplasmic reticulum in the form of heterodimer with protein prM. They play a role in virion budding in the ER, and the newly formed immature particule is covered with 60 spikes composed of heterodimer between precursor prM and envelope protein E. The virion is transported to the Golgi apparatus where the low pH causes dissociation of PrM-E heterodimers and formation of E homodimers. prM-E cleavage is ineficient, and many virions are only partially matured. These uncleaved prM would play a role in immune evasion.[UniProtKB:P17763] Non-structural protein 1: Involved in immune evasion, pathogenesis and viral replication. Once cleaved off the polyprotein, is targeted to three destinations: the viral replication cycle, the plasma membrane and the extracellular compartment. May play a role in viral genome replication. Assist membrane bending and envelopment of genomic RNA at the endoplasmic reticulum. Excreted as a hexameric lipoparticle that plays a role against host immune responce.[UniProtKB:P17763] Non-structural protein 2A: Component of the viral RNA replication complex that functions in virion assembly and antagonizes the host immune response.[UniProtKB:P17763] Non-structural protein 2B: Required cofactor for the serine protease function of NS3 (By similarity). May have membrane-destabilizing activity and form viroporins (By similarity).[UniProtKB:P17763][PROSITE-ProRule:PRU00859] Serine protease NS3: Displays three enzymatic activities: serine protease, NTPase and RNA helicase. NS3 serine protease, in association with NS2B, performs its autocleavage and cleaves the polyprotein at dibasic sites in the cytoplasm: C-prM, NS2A-NS2B, NS2B-NS3, NS3-NS4A, NS4A-2K and NS4B-NS5. NS3 RNA helicase binds RNA and unwinds dsRNA in the 3' to 5' direction.[PROSITE-ProRule:PRU00860] Non-structural protein 4A: Induces host endoplasmic regulate the ATPase activity of the NS3 helicase.[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] RNA-directed RNA polymerase NS5: Replicates the viral (+) and (-) genome, and performs the capping of genomes in the cytoplasm. NS5 methylates viral RNA cap at guanine N-7 and ribose 2'-O positions. Besides its role in genome replication, also prevents the establishment of cellular antiviral state by blocking the interferon-alpha/beta (IFN-alpha/beta) signaling pathway. Inhibits host TYK2 and STAT2 phosphorylation, thereby preventing activation of JAK-STAT signaling pathway.[UniProtKB:P17763]

See Also

• Nonstructural protein 3D structures

References

1. ↑ Chandramouli S, Joseph JS, Daudenarde S, Gatchalian J, Cornillez-Ty C, Kuhn P. Serotype-specific structural differences in the protease-cofactor complexes of the dengue virus family. J Virol. 2010 Mar;84(6):3059-67. Epub 2009 Dec 30. PMID:20042502 doi:10.1128/JVI.02044-09