View source for 2wrb


==the structure of influenza H2 human singapore hemagglutinin with avian receptor==
<StructureSection load='2wrb' size='340' side='right'caption='[[2wrb]], [[Resolution|resolution]] 3.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2wrb]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Influenza_A_virus Influenza A virus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2WRB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2WRB 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]] 3.1&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><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=2wrb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2wrb OCA], [https://pdbe.org/2wrb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2wrb RCSB], [https://www.ebi.ac.uk/pdbsum/2wrb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2wrb ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/HEMA_I57A5 HEMA_I57A5] 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 either through clathrin-dependent endocytosis or through 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.[HAMAP-Rule:MF_04072]
== 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/wr/2wrb_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=2wrb ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The viruses that caused the three influenza pandemics of the twentieth century in 1918, 1957, and 1968 had distinct hemagglutinin receptor binding glycoproteins that had evolved the capacity to recognize human cell receptors. We have determined the structure of the H2 hemagglutinin from the second pandemic, the "Asian Influenza" of 1957. We compare it with the 1918 "Spanish Influenza" hemagglutinin, H1, and the 1968 "Hong Kong Influenza" hemagglutinin, H3, and show that despite its close overall structural similarity to H1, and its more distant relationship to H3, the H2 receptor binding site is closely related to that of H3 hemagglutinin. By analyzing hemagglutinins of potential H2 avian precursors of the pandemic virus, we show that the human receptor can be bound by avian hemagglutinins that lack the human-specific mutations of H2 and H3 pandemic viruses, Gln-226Leu, and Gly-228Ser. We show how Gln-226 in the avian H2 receptor binding site, together with Asn-186, form hydrogen bond networks through bound water molecules to mediate binding to human receptor. We show that the human receptor adopts a very similar conformation in both human and avian hemagglutinin-receptor complexes. We also show that Leu-226 in the receptor binding site of human virus hemagglutinins creates a hydrophobic environment near the Sia-1-Gal-2 glycosidic linkage that favors binding of the human receptor and is unfavorable for avian receptor binding. We consider the significance for the development of pandemics, of the existence of avian viruses that can bind to both avian and human receptors.

Structures of receptor complexes formed by hemagglutinins from the Asian Influenza pandemic of 1957.,Liu J, Stevens DJ, Haire LF, Walker PA, Coombs PJ, Russell RJ, Gamblin SJ, Skehel JJ Proc Natl Acad Sci U S A. 2009 Oct 6;106(40):17175-80. Epub 2009 Sep 28. PMID:19805083<ref>PMID:19805083</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 2wrb" style="background-color:#fffaf0;"></div>

==See Also==
*[[Hemagglutinin 3D structures|Hemagglutinin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Influenza A virus]]
[[Category: Large Structures]]
[[Category: Coombs PJ]]
[[Category: Gamblin SJ]]
[[Category: Haire LF]]
[[Category: Liu J]]
[[Category: Russell RJ]]
[[Category: Skehel JJ]]
[[Category: Stevens DJ]]
[[Category: Walker PA]]