View source for 3htt


==The hemagglutinin structure of an avian H1N1 influenza A virus in complex with 2,3-sialyllactose==
<StructureSection load='3htt' size='340' side='right'caption='[[3htt]], [[Resolution|resolution]] 2.95&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3htt]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Influenza_A_virus_(A/WDK/JX/12416/2005(H1N1)) Influenza A virus (A/WDK/JX/12416/2005(H1N1))]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3HTT OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3HTT 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]] 2.95&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GAL:BETA-D-GALACTOSE'>GAL</scene>, <scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=NDG:2-(ACETYLAMINO)-2-DEOXY-A-D-GLUCOPYRANOSE'>NDG</scene>, <scene name='pdbligand=PRD_900025:3-sialyl-alpha-lactose'>PRD_900025</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=3htt FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3htt OCA], [https://pdbe.org/3htt PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3htt RCSB], [https://www.ebi.ac.uk/pdbsum/3htt PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3htt ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/C7C6F1_9INFA C7C6F1_9INFA] 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/ht/3htt_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.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=3htt ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The interaction between hemagglutinin (HA) and receptors is a kernel in the study of evolution and host adaptation of H1N1 influenza A viruses. The notion that the avian HA is associated with preferential specificity for receptors with Siaalpha2,3Gal glycosidic linkage over those with Siaalpha2,6Gal linkage is not all consistent with the available data on H1N1 viruses. By x-ray crystallography, the HA structure of an avian H1N1 influenza A virus, as well as its complexes with the receptor analogs, was determined. The structures revealed no preferential binding of avian receptor analogs over that of the human analog, suggesting that the HA/receptor binding might not be as stringent as is commonly believed in determining the host receptor preference for some subtypes of influenza viruses, such as the H1N1 viruses. The structure also showed difference in glycosylation despite the preservation of related sequences, which may partly contribute to the difference between structures of human and avian origin.

The hemagglutinin structure of an avian H1N1 influenza A virus.,Lin T, Wang G, Li A, Zhang Q, Wu C, Zhang R, Cai Q, Song W, Yuen KY Virology. 2009 Sep 15;392(1):73-81. Epub 2009 Jul 22. PMID:19628241<ref>PMID:19628241</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 3htt" style="background-color:#fffaf0;"></div>

==See Also==
*[[Hemagglutinin 3D structures|Hemagglutinin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Cai Q]]
[[Category: Li A]]
[[Category: Song W]]
[[Category: Wang G]]
[[Category: Wu C]]
[[Category: Yuen K-Y]]
[[Category: Zhang Q]]
[[Category: Zhang R]]