View source for 1zvb


==A structure-based mechanism of SARS virus membrane fusion==
<StructureSection load='1zvb' size='340' side='right'caption='[[1zvb]], [[Resolution|resolution]] 1.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1zvb]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Severe_acute_respiratory_syndrome-related_coronavirus Severe acute respiratory syndrome-related coronavirus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ZVB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1ZVB 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]] 1.7&#8491;</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=1zvb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1zvb OCA], [https://pdbe.org/1zvb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1zvb RCSB], [https://www.ebi.ac.uk/pdbsum/1zvb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1zvb ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/SPIKE_SARS SPIKE_SARS] May down-regulate host tetherin (BST2) by lysosomal degradation, thereby counteracting its antiviral activity.<ref>PMID:31199522</ref>   Attaches the virion to the cell membrane by interacting with host receptor, initiating the infection (By similarity). Binding to human ACE2 and CLEC4M/DC-SIGNR receptors and internalization of the virus into the endosomes of the host cell induces conformational changes in the S glycoprotein. Proteolysis by cathepsin CTSL may unmask the fusion peptide of S2 and activate membrane fusion within endosomes.[HAMAP-Rule:MF_04099]<ref>PMID:14670965</ref> <ref>PMID:15496474</ref>   Mediates fusion of the virion and cellular membranes by acting as a class I viral fusion protein. Under the current model, the protein has at least three conformational states: pre-fusion native state, pre-hairpin intermediate state, and post-fusion hairpin state. During viral and target cell membrane fusion, the coiled coil regions (heptad repeats) assume a trimer-of-hairpins structure, positioning the fusion peptide in close proximity to the C-terminal region of the ectodomain. The formation of this structure appears to drive apposition and subsequent fusion of viral and target cell membranes.[HAMAP-Rule:MF_04099]  Acts as a viral fusion peptide which is unmasked following S2 cleavage occurring upon virus endocytosis.[HAMAP-Rule:MF_04099]<ref>PMID:19321428</ref> 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/zv/1zvb_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1zvb ConSurf].
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== Publication Abstract from PubMed ==
Entry of SARS coronavirus into its target cell requires large-scale structural transitions in the viral spike (S) glycoprotein in order to induce fusion of the virus and cell membranes. Here we describe the identification and crystal structures of four distinct alpha-helical domains derived from the highly conserved heptad-repeat (HR) regions of the S2 fusion subunit. The four domains are an antiparallel four-stranded coiled coil, a parallel trimeric coiled coil, a four-helix bundle, and a six-helix bundle that is likely the final fusogenic form of the protein. When considered together, the structural and thermodynamic features of the four domains suggest a possible mechanism whereby the HR regions, initially sequestered in the native S glycoprotein spike, are released and refold sequentially to promote membrane fusion. Our results provide a structural framework for understanding the control of membrane fusion and should guide efforts to intervene in the SARS coronavirus entry process.

Structures and polymorphic interactions of two heptad-repeat regions of the SARS virus S2 protein.,Deng Y, Liu J, Zheng Q, Yong W, Lu M Structure. 2006 May;14(5):889-99. PMID:16698550<ref>PMID:16698550</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 1zvb" style="background-color:#fffaf0;"></div>

==See Also==
*[[Sandbox 3001|Sandbox 3001]]
*[[Spike protein|Spike protein]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Severe acute respiratory syndrome-related coronavirus]]
[[Category: Dai J]]
[[Category: Deng Y]]
[[Category: Liu J]]
[[Category: Lu M]]
[[Category: Yong W]]
[[Category: Zheng Q]]