View source for 1qfu


==INFLUENZA VIRUS HEMAGGLUTININ COMPLEXED WITH A NEUTRALIZING ANTIBODY==
<StructureSection load='1qfu' size='340' side='right'caption='[[1qfu]], [[Resolution|resolution]] 2.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1qfu]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Influenza_A_virus_(A/X-31(H3N2)) Influenza A virus (A/X-31(H3N2))] and [https://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. The April 2006 RCSB PDB [https://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/index.html Molecule of the Month] feature on ''Hemagglutinin''  by David S. Goodsell is [https://dx.doi.org/10.2210/rcsb_pdb/mom_2006_4 10.2210/rcsb_pdb/mom_2006_4]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QFU OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1QFU 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]] 2.8&#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=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=NDG:2-(ACETYLAMINO)-2-DEOXY-A-D-GLUCOPYRANOSE'>NDG</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=1qfu FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1qfu OCA], [https://pdbe.org/1qfu PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1qfu RCSB], [https://www.ebi.ac.uk/pdbsum/1qfu PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1qfu ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/HEMA_I000X HEMA_I000X] 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.<ref>PMID:15122347</ref>   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/qf/1qfu_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=1qfu ConSurf].
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== Publication Abstract from PubMed ==
The structure of a complex of influenza hemagglutinin (HA) with a neutralizing antibody shows that the antibody binds to HA at a distance from the virus receptor binding site. Comparison of the properties of this antibody and its Fab with those of an antibody that recognizes an epitope overlapping the receptor binding site leads to two main conclusions. First, inhibition of receptor binding is an important component of neutralization. Second, the efficiency of neutralization by the antibodies ranks in the same order as their avidities for HA, and their large size makes these antibodies highly efficient at neutralization, regardless of the location of their epitope in relation to the virus receptor binding site. These observations provide rationales for the range of antibody specificities that are detected in immune sera and for the distribution of sequence changes on the membrane-distal surface of influenza HAs that occur during 'antigenic drift.'

A complex of influenza hemagglutinin with a neutralizing antibody that binds outside the virus receptor binding site.,Fleury D, Barrere B, Bizebard T, Daniels RS, Skehel JJ, Knossow M Nat Struct Biol. 1999 Jun;6(6):530-4. PMID:10360354<ref>PMID:10360354</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 1qfu" style="background-color:#fffaf0;"></div>

==See Also==
*[[Hemagglutinin 3D structures|Hemagglutinin 3D structures]]
*[[Monoclonal Antibodies 3D structures|Monoclonal Antibodies 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Hemagglutinin]]
[[Category: Large Structures]]
[[Category: Mus musculus]]
[[Category: RCSB PDB Molecule of the Month]]
[[Category: Bizebard T]]
[[Category: Daniels RS]]
[[Category: Fleury D]]
[[Category: Gigant B]]
[[Category: Knossow M]]
[[Category: Skehel JJ]]