1ok8: Difference between revisions
No edit summary |
No edit summary |
||
| (19 intermediate revisions by the same user not shown) | |||
| Line 1: | Line 1: | ||
== | ==Crystal structure of the dengue 2 virus envelope glycoprotein in the postfusion conformation== | ||
Dengue virus enters a host cell when the viral envelope glycoprotein, E, binds to a receptor and responds by conformational rearrangement to the | <StructureSection load='1ok8' size='340' side='right'caption='[[1ok8]], [[Resolution|resolution]] 2.00Å' scene=''> | ||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1ok8]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Dengue_virus_2 Dengue virus 2]. The July 2008 RCSB PDB [https://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/index.html Molecule of the Month] feature on ''Dengue Virus'' by David Goodsell is [https://dx.doi.org/10.2210/rcsb_pdb/mom_2008_7 10.2210/rcsb_pdb/mom_2008_7]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1OK8 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1OK8 FirstGlance]. <br> | |||
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></td></tr> | |||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1ok8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ok8 OCA], [https://pdbe.org/1ok8 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1ok8 RCSB], [https://www.ebi.ac.uk/pdbsum/1ok8 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1ok8 ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/POLG_DEN2P POLG_DEN2P] 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). | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Dengue virus enters a host cell when the viral envelope glycoprotein, E, binds to a receptor and responds by conformational rearrangement to the reduced pH of an endosome. The conformational change induces fusion of viral and host-cell membranes. A three-dimensional structure of the soluble E ectodomain (sE) in its trimeric, postfusion state reveals striking differences from the dimeric, prefusion form. The elongated trimer bears three 'fusion loops' at one end, to insert into the host-cell membrane. Their structure allows us to model directly how these fusion loops interact with a lipid bilayer. The protein folds back on itself, directing its carboxy terminus towards the fusion loops. We propose a fusion mechanism driven by essentially irreversible conformational changes in E and facilitated by fusion-loop insertion into the outer bilayer leaflet. Specific features of the folded-back structure suggest strategies for inhibiting flavivirus entry. | |||
Structure of the dengue virus envelope protein after membrane fusion.,Modis Y, Ogata S, Clements D, Harrison SC Nature. 2004 Jan 22;427(6972):313-9. PMID:14737159<ref>PMID:14737159</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 1ok8" style="background-color:#fffaf0;"></div> | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: | [[Category: Dengue Virus]] | ||
[[Category: | [[Category: Dengue virus 2]] | ||
[[Category: | [[Category: Large Structures]] | ||
[[Category: | [[Category: RCSB PDB Molecule of the Month]] | ||
[[Category: | [[Category: Harrison SC]] | ||
[[Category: | [[Category: Modis Y]] | ||