View source for 2yp4


==Haemagglutinin of 2004 Human H3N2 Virus in Complex with Human Receptor Analogue LSTc==
<StructureSection load='2yp4' size='340' side='right'caption='[[2yp4]], [[Resolution|resolution]] 1.85&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2yp4]] is a 1 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=2YP4 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2YP4 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]] 1.85&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BGC:BETA-D-GLUCOSE'>BGC</scene>, <scene name='pdbligand=EPE:4-(2-HYDROXYETHYL)-1-PIPERAZINE+ETHANESULFONIC+ACID'>EPE</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=SIA:O-SIALIC+ACID'>SIA</scene>, <scene name='pdbligand=TAM:TRIS(HYDROXYETHYL)AMINOMETHANE'>TAM</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=2yp4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2yp4 OCA], [https://pdbe.org/2yp4 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2yp4 RCSB], [https://www.ebi.ac.uk/pdbsum/2yp4 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2yp4 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/K7N5L2_9INFA K7N5L2_9INFA] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The hemagglutinin (HA) of influenza A(H3N2) virus responsible for the 1968 influenza pandemic derived from an avian virus. On introduction into humans, its receptor binding properties had changed from a preference for avian receptors (alpha2,3-linked sialic acid) to a preference for human receptors (alpha2,6-linked sialic acid). By 2001, the avidity of human H3 viruses for avian receptors had declined, and since then the affinity for human receptors has also decreased significantly. These changes in receptor binding, which correlate with increased difficulties in virus propagation in vitro and in antigenic analysis, have been assessed by virus hemagglutination of erythrocytes from different species and quantified by measuring virus binding to receptor analogs using surface biolayer interferometry. Crystal structures of HA-receptor analog complexes formed with HAs from viruses isolated in 2004 and 2005 reveal significant differences in the conformation of the 220-loop of HA1, relative to the 1968 structure, resulting in altered interactions between the HA and the receptor analog that explain the changes in receptor affinity. Site-specific mutagenesis shows the HA1 Asp-225--&gt;Asn substitution to be the key determinant of the decreased receptor binding in viruses circulating since 2005. Our results indicate that the evolution of human influenza A(H3N2) viruses since 1968 has produced a virus with a low propensity to bind human receptor analogs, and this loss of avidity correlates with the marked reduction in A(H3N2) virus disease impact in the last 10 y.

Evolution of the receptor binding properties of the influenza A(H3N2) hemagglutinin.,Lin YP, Xiong X, Wharton SA, Martin SR, Coombs PJ, Vachieri SG, Christodoulou E, Walker PA, Liu J, Skehel JJ, Gamblin SJ, Hay AJ, Daniels RS, McCauley JW Proc Natl Acad Sci U S A. 2012 Dec 26;109(52):21474-9. doi:, 10.1073/pnas.1218841110. Epub 2012 Dec 10. PMID:23236176<ref>PMID:23236176</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 2yp4" 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: Christodoulou E]]
[[Category: Coombs PJ]]
[[Category: Daniels RS]]
[[Category: Gamblin SJ]]
[[Category: Hay AJ]]
[[Category: Lin YP]]
[[Category: Liu J]]
[[Category: Martin SR]]
[[Category: McCauley JW]]
[[Category: Skehel JJ]]
[[Category: Vachieri SG]]
[[Category: Walker PA]]
[[Category: Wharton SA]]
[[Category: Xiong X]]