6m3w

==Post-fusion structure of SARS-CoV spike glycoprotein==

<StructureSection load='6m3w' size='340' side='right'caption='[[6m3w]], [[Resolution|resolution]] 3.90&Aring;' scene=''>

<table><tr><td colspan='2'>[[6m3w]] is a 3 chain structure with sequence from [http://en.wikipedia.org/wiki/Hcov-sars Hcov-sars]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6M3W OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=6M3W FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></td></tr>

<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">S, 2 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=694009 HCoV-SARS])</td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=6m3w FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6m3w OCA], [http://pdbe.org/6m3w PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6m3w RCSB], [http://www.ebi.ac.uk/pdbsum/6m3w PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6m3w ProSAT]</span></td></tr>

== Function ==

[[http://www.uniprot.org/uniprot/SPIKE_CVHSA SPIKE_CVHSA]] S1 attaches the virion to the cell membrane by interacting with human ACE2 and CLEC4M/DC-SIGNR, initiating the infection. Binding to the receptor and internalization of the virus into the endosomes of the host cell probably induces conformational changes in the S glycoprotein. Proteolysis by cathepsin CTSL may unmask the fusion peptide of S2 and activate membranes fusion within endosomes. S2 is 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.

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== Publication Abstract from PubMed ==

Global emergencies caused by the severe acute respiratory syndrome coronavirus (SARS-CoV), Middle-East respiratory syndrome coronavirus (MERS-CoV) and SARS-CoV-2 significantly endanger human health. The spike (S) glycoprotein is the key antigen and its conserved S2 subunit contributes to viral entry by mediating host-viral membrane fusion. However, structural information of the post-fusion S2 from these highly pathogenic human-infecting coronaviruses is still lacking. We used single-particle cryo-electron microscopy to show that the post-fusion SARS-CoV S2 forms a further rotated HR1-HR2 six-helix bundle and a tightly bound linker region upstream of the HR2 motif. The structures of pre- and post-fusion SARS-CoV S glycoprotein dramatically differ, resembling that of the Mouse hepatitis virus (MHV) and other class I viral fusion proteins. This structure suggests potential targets for the development of vaccines and therapies against a wide range of SARS-like coronaviruses.

Cryo-EM analysis of the post-fusion structure of the SARS-CoV spike glycoprotein.,Fan X, Cao D, Kong L, Zhang X Nat Commun. 2020 Jul 17;11(1):3618. doi: 10.1038/s41467-020-17371-6. PMID:32681106<ref>PMID:32681106</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 6m3w" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Hcov-sars]]

[[Category: Cao, D]]

[[Category: Viral protein]]