View source for 4hf5


==Crystal structure of Fab 8F8 in complex a H2N2 influenza virus hemagglutinin==
<StructureSection load='4hf5' size='340' side='right'caption='[[4hf5]], [[Resolution|resolution]] 3.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4hf5]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [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=4HF5 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4HF5 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]] 3.004&#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=MAN:ALPHA-D-MANNOSE'>MAN</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</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=4hf5 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4hf5 OCA], [https://pdbe.org/4hf5 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4hf5 RCSB], [https://www.ebi.ac.uk/pdbsum/4hf5 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4hf5 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]
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== Publication Abstract from PubMed ==
Influenza virus hemagglutinin (HA) mediates receptor binding and viral entry during influenza infection. The development of receptor analogs as viral-entry blockers has not been successful, which suggests that sialic acid may not be an ideal scaffold to obtain broad, potent HA inhibitors. Here, we report crystal structures of Fab fragments from three human antibodies that neutralize the 1957 pandemic H2N2 influenza virus in complex with H2 HA. All three antibodies use an aromatic residue to plug a conserved cavity in the HA receptor-binding site. Each antibody interacts with the absolutely conserved HA1 Trp153 at the cavity base through pi-pi stacking with the signature Phe54 of two VH1-69-encoded antibodies or a tyrosine from HCDR3 in the other antibody. This highly conserved interaction can be used as a starting point to design inhibitors targeting this conserved hydrophobic pocket in influenza viruses.

A recurring motif for antibody recognition of the receptor-binding site of influenza hemagglutinin.,Xu R, Krause JC, McBride R, Paulson JC, Crowe JE Jr, Wilson IA Nat Struct Mol Biol. 2013 Mar;20(3):363-70. doi: 10.1038/nsmb.2500. Epub 2013 Feb, 10. PMID:23396351<ref>PMID:23396351</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 4hf5" style="background-color:#fffaf0;"></div>

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