View source for 6tzb


==Crystal structure of the A/Hong Kong/1/1968 (H3N2) influenza virus hemagglutinin in complex with 6'-SLNLN==
<StructureSection load='6tzb' size='340' side='right'caption='[[6tzb]], [[Resolution|resolution]] 2.24&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6tzb]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Influenza_A_virus_(A/Hong_Kong/1/1968(H3N2)) Influenza A virus (A/Hong Kong/1/1968(H3N2))]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6TZB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6TZB 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]] 2.243&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BMA:BETA-D-MANNOSE'>BMA</scene>, <scene name='pdbligand=GAL:BETA-D-GALACTOSE'>GAL</scene>, <scene name='pdbligand=MAN:ALPHA-D-MANNOSE'>MAN</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=PRD_900046:6-sialyl-N-acetyllactosamine'>PRD_900046</scene>, <scene name='pdbligand=SIA:O-SIALIC+ACID'>SIA</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=6tzb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6tzb OCA], [https://pdbe.org/6tzb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6tzb RCSB], [https://www.ebi.ac.uk/pdbsum/6tzb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6tzb ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/HEMA_I68A4 HEMA_I68A4] Binds to sialic acid-containing receptors on the cell surface, bringing about the attachment of the virus particle to the cell. This attachment induces virion internalization of about two third of the virus particles through clathrin-dependent endocytosis and about one third through a clathrin- and caveolin-independent pathway. Plays a major role in the determination of host range restriction and virulence. Class I viral fusion protein. Responsible for penetration of the virus into the cell cytoplasm by mediating the fusion of the membrane of the endocytosed virus particle with the endosomal membrane. Low pH in endosomes induces an irreversible conformational change in HA2, releasing the fusion hydrophobic peptide. Several trimers are required to form a competent fusion pore (By similarity).
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Antigenic drift of influenza virus hemagglutinin (HA) is enabled by facile evolvability. However, HA antigenic site B, which has become immunodominant in recent human H3N2 influenza viruses, is also evolutionarily constrained by its involvement in receptor binding. Here, we employ deep mutational scanning to probe the local fitness landscape of HA antigenic site B in six different human H3N2 strains spanning from 1968 to 2016. We observe that the fitness landscape of HA antigenic site B can be very different between strains. Sequence variants that exhibit high fitness in one strain can be deleterious in another, indicating that the evolutionary constraints of antigenic site B have changed over time. Structural analysis suggests that the local fitness landscape of antigenic site B can be reshaped by natural mutations via modulation of the receptor-binding mode. Overall, these findings elucidate how influenza virus continues to explore new antigenic space despite strong functional constraints.

Major antigenic site B of human influenza H3N2 viruses has an evolving local fitness landscape.,Wu NC, Otwinowski J, Thompson AJ, Nycholat CM, Nourmohammad A, Wilson IA Nat Commun. 2020 Mar 6;11(1):1233. doi: 10.1038/s41467-020-15102-5. PMID:32144244<ref>PMID:32144244</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6tzb" style="background-color:#fffaf0;"></div>

==See Also==
*[[Hemagglutinin 3D structures|Hemagglutinin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Wilson IA]]
[[Category: Wu NC]]