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| | <StructureSection load='5h9c' size='340' side='right'caption='[[5h9c]], [[Resolution|resolution]] 1.78Å' scene=''> | | <StructureSection load='5h9c' size='340' side='right'caption='[[5h9c]], [[Resolution|resolution]] 1.78Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[5h9c]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Avian_leukosis_virus_rsa Avian leukosis virus rsa]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5H9C OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5H9C FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[5h9c]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Rous_sarcoma_virus_(strain_Schmidt-Ruppin_A) Rous sarcoma virus (strain Schmidt-Ruppin A)]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5H9C OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5H9C FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.783Å</td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[4jpr|4jpr]]</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></td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">env ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=269446 Avian leukosis virus RSA])</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=5h9c FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5h9c OCA], [https://pdbe.org/5h9c PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5h9c RCSB], [https://www.ebi.ac.uk/pdbsum/5h9c PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5h9c ProSAT]</span></td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5h9c FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5h9c OCA], [http://pdbe.org/5h9c PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5h9c RCSB], [http://www.ebi.ac.uk/pdbsum/5h9c PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5h9c ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/ENV_RSVSA ENV_RSVSA]] The surface protein (SU) attaches the virus to the host cell by binding to its receptor. This interaction triggers the refolding of the transmembrane protein (TM) and is thought to activate its fusogenic potential by unmasking its fusion peptide. Fusion occurs at the host cell plasma membrane (By similarity). The transmembrane protein (TM) acts as a class I viral fusion protein. Under the current model, the protein has at least 3 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. Membranes fusion leads to delivery of the nucleocapsid into the cytoplasm (By similarity). | + | [https://www.uniprot.org/uniprot/ENV_RSVSA ENV_RSVSA] The surface protein (SU) attaches the virus to the host cell by binding to its receptor. This interaction triggers the refolding of the transmembrane protein (TM) and is thought to activate its fusogenic potential by unmasking its fusion peptide. Fusion occurs at the host cell plasma membrane (By similarity). The transmembrane protein (TM) acts as a class I viral fusion protein. Under the current model, the protein has at least 3 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. Membranes fusion leads to delivery of the nucleocapsid into the cytoplasm (By similarity). |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Avian leukosis virus rsa]] | |
| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| - | [[Category: Aydin, H]] | + | [[Category: Aydin H]] |
| - | [[Category: Lee, J E]] | + | [[Category: Lee JE]] |
| - | [[Category: Aslv]]
| + | |
| - | [[Category: Entry]]
| + | |
| - | [[Category: Fusion]]
| + | |
| - | [[Category: Glycoprotein]]
| + | |
| - | [[Category: Viral protein]]
| + | |
| - | [[Category: Virus]]
| + | |
| Structural highlights
Function
ENV_RSVSA The surface protein (SU) attaches the virus to the host cell by binding to its receptor. This interaction triggers the refolding of the transmembrane protein (TM) and is thought to activate its fusogenic potential by unmasking its fusion peptide. Fusion occurs at the host cell plasma membrane (By similarity). The transmembrane protein (TM) acts as a class I viral fusion protein. Under the current model, the protein has at least 3 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. Membranes fusion leads to delivery of the nucleocapsid into the cytoplasm (By similarity).
Publication Abstract from PubMed
Entry of enveloped viruses into host cells is mediated by their surface envelope glycoproteins (Env). On the surface of the virus, Env is in a metastable, prefusion state, primed to catalyze the fusion of the viral and host membranes. An external trigger is needed to promote the drastic conformational changes necessary for the fusion subunit to fold into the low-energy, 6-helix bundle. These triggers typically facilitate pH-independent entry at the plasma membrane or pH-dependent entry in a low-pH endosomal compartment. The alpha-retrovirus avian sarcoma leukosis virus (ASLV) has a rare, 2-step entry mechanism with both pH-dependent and pH-independent features. Here, we present the 2.0-A-resolution crystal structure of the ASLV transmembrane (TM) fusion protein. Our structural and biophysical studies indicated that unlike other pH-dependent or pH-independent viral TMs, the ASLV fusion subunit is stable irrespective of pH. Two histidine residues (His490 and His492) in the chain reversal region confer stability at low pH. A structural comparison of class I viral fusion proteins suggests that the presence of a positive charge, either a histidine or arginine amino acid, stabilizes a helical dipole moment and is a signature of fusion proteins active at low pH. The structure now reveals key residues and features that explain its 2-step mechanism, and we discuss the implications of the ASLV TM structure in the context of general mechanisms required for membrane fusion.-Aydin, H., Smrke, B.M., Lee, J. E. Structural characterization of a fusion glycoprotein from a retrovirus that undergoes a hybrid 2-step entry mechanism.
Structural characterization of a fusion glycoprotein from a retrovirus that undergoes a hybrid 2-step entry mechanism.,Aydin H, Smrke BM, Lee JE FASEB J. 2013 Sep 13. PMID:24036886[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Aydin H, Smrke BM, Lee JE. Structural characterization of a fusion glycoprotein from a retrovirus that undergoes a hybrid 2-step entry mechanism. FASEB J. 2013 Sep 13. PMID:24036886 doi:10.1096/fj.13-232371
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