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| <StructureSection load='6xw7' size='340' side='right'caption='[[6xw7]], [[Resolution|resolution]] 2.15Å' scene=''> | | <StructureSection load='6xw7' size='340' side='right'caption='[[6xw7]], [[Resolution|resolution]] 2.15Å' scene=''> |
| == Structural highlights == | | == Structural highlights == |
| <table><tr><td colspan='2'>[[6xw7]] is a 8 chain structure with sequence from [https://en.wikipedia.org/wiki/Murine_norovirus_1 Murine norovirus 1] and [https://en.wikipedia.org/wiki/Vicugna_pacos Vicugna pacos]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6XW7 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6XW7 FirstGlance]. <br> | | <table><tr><td colspan='2'>Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6XW7 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6XW7 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]] 2.15Å</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]] 2.15Å</td></tr> |
| <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CHO:GLYCOCHENODEOXYCHOLIC+ACID'>CHO</scene>, <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene></td></tr> | | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CHO:GLYCOCHENODEOXYCHOLIC+ACID'>CHO</scene>, <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</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=6xw7 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6xw7 OCA], [https://pdbe.org/6xw7 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6xw7 RCSB], [https://www.ebi.ac.uk/pdbsum/6xw7 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6xw7 ProSAT]</span></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=6xw7 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6xw7 OCA], [https://pdbe.org/6xw7 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6xw7 RCSB], [https://www.ebi.ac.uk/pdbsum/6xw7 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6xw7 ProSAT]</span></td></tr> |
| </table> | | </table> |
| == Function ==
| |
| [https://www.uniprot.org/uniprot/Q80J94_9CALI Q80J94_9CALI]
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| <div style="background-color:#fffaf0;">
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| == Publication Abstract from PubMed ==
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| Human norovirus frequently causes outbreaks of acute gastroenteritis. Although discovered more than five decades ago, antiviral development has, until recently, been hampered by the lack of a reliable human norovirus cell culture system. Nevertheless, a lot of pathogenesis studies were accomplished using murine norovirus (MNV), which can be grown routinely in cell culture. In this study, we analysed a sizeable library of Nanobodies that were raised against the murine norovirus virion with the main purpose of developing Nanobody-based inhibitors. We discovered two types of neutralizing Nanobodies and analysed the inhibition mechanisms using X-ray crystallography, cryo-EM, and cell culture techniques. The first type bound on the top region of the protruding (P) domain. Interestingly, the Nanobody binding region closely overlapped the MNV receptor-binding site and collectively shared numerous P domain-binding residues. In addition, we showed that these Nanobodies competed with the soluble receptor and this action blocked virion attachment to cultured cells. The second type bound at a dimeric interface on the lower side of the P dimer. We discovered that these Nanobodies disrupted a structural change in the capsid associated with binding co-factors (i.e., metal cations/bile acid). Indeed, we found that capsids underwent major conformational changes following addition of Mg(2+) or Ca(2+) Ultimately, these Nanobodies directly obstructed a structural modification reserved for a post-receptor attachment stage. Altogether, our new data show that Nanobody-based inhibition could occur by blocking functional and structural capsid properties.IMPORTANCE This research discovered and analysed two different types of MNV neutralizing Nanobodies. The top-binding Nanobodies sterically inhibited the receptor-binding site, whereas the dimeric-binding Nanobodies interfered with a structural modification associated with co-factor binding. Moreover, we found that the capsid contained a number of vulnerable regions that were essential for viral replication. In fact, the capsid appeared to be organized in a state of flux, which could be important for co-factor/receptor binding functions. Blocking these capsid-binding events with Nanobodies directly inhibited essential capsid functions. Moreover, a number of MNV-specific Nanobody binding epitopes were comparable to human norovirus-specific Nanobody inhibitors. Therefore, this additional structural and inhibition information could be further exploited in the development of human norovirus antivirals.
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| Nanobody mediated neutralization reveals an Achilles heel for norovirus.,Koromyslova AD, Devant JM, Kilic T, Sabin CD, Malak V, Hansman GS J Virol. 2020 Apr 22. pii: JVI.00660-20. doi: 10.1128/JVI.00660-20. PMID:32321816<ref>PMID:32321816</ref>
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| From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
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| </div>
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| <div class="pdbe-citations 6xw7" style="background-color:#fffaf0;"></div>
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| ==See Also== | | ==See Also== |
| *[[Virus coat proteins 3D structures|Virus coat proteins 3D structures]] | | *[[Virus coat proteins 3D structures|Virus coat proteins 3D structures]] |
| == References ==
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| <references/>
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| __TOC__ | | __TOC__ |
| </StructureSection> | | </StructureSection> |
| [[Category: Large Structures]] | | [[Category: Large Structures]] |
| [[Category: Murine norovirus 1]]
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| [[Category: Vicugna pacos]]
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| [[Category: Hansman G]] | | [[Category: Hansman G]] |
| [[Category: Kilic T]] | | [[Category: Kilic T]] |
| [[Category: Sabin C]] | | [[Category: Sabin C]] |