View source for 3ku6


==Crystal structure of a H2N2 influenza virus hemagglutinin, 226L/228G==
<StructureSection load='3ku6' size='340' side='right'caption='[[3ku6]], [[Resolution|resolution]] 1.75&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3ku6]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Influenza_A_virus_(A/Japan/305/1957(H2N2)) Influenza A virus (A/Japan/305/1957(H2N2))]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3KU6 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3KU6 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]] 1.75&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=PEG:DI(HYDROXYETHYL)ETHER'>PEG</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=3ku6 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3ku6 OCA], [https://pdbe.org/3ku6 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3ku6 RCSB], [https://www.ebi.ac.uk/pdbsum/3ku6 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3ku6 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/C7S226_I57A0 C7S226_I57A0] 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).[RuleBase:RU003324][SAAS:SAAS013829_004_327643]
== 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/ku/3ku6_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=3ku6 ConSurf].
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== Publication Abstract from PubMed ==
The hemagglutinin (HA) envelope protein of influenza viruses mediates essential viral functions, including receptor binding and membrane fusion, and is the major viral antigen for antibody neutralization. The 1957 H2N2 subtype (Asian flu) was one of the three great influenza pandemics of the last century and caused 1 million deaths globally from 1957 to 1968. Three crystal structures of 1957 H2 HAs have been determined at 1.60 to 1.75 A resolutions to investigate the structural basis for their antigenicity and evolution from avian to human binding specificity that contributed to its introduction into the human population. These structures, which represent the highest resolutions yet recorded for a complete ectodomain of a glycosylated viral surface antigen, along with the results of glycan microarray binding analysis, suggest that a hydrophobicity switch at residue 226 and elongation of receptor-binding sites were both critical for avian H2 HA to acquire human receptor specificity. H2 influenza viruses continue to circulate in birds and pigs and, therefore, remain a substantial threat for transmission to humans. The H2 HA structure also reveals a highly conserved epitope that could be harnessed in the design of a broader and more universal influenza A virus vaccine.

Structure, receptor binding, and antigenicity of influenza virus hemagglutinins from the 1957 H2N2 pandemic.,Xu R, McBride R, Paulson JC, Basler CF, Wilson IA J Virol. 2010 Feb;84(4):1715-21. Epub 2009 Dec 9. PMID:20007271<ref>PMID:20007271</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 3ku6" style="background-color:#fffaf0;"></div>

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