Structural highlights
Function[HEMA_I68A0] 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. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe structure of a complex between the hemagglutinin of influenza virus and the Fab of a neutralizing antibody was determined by X-ray crystallography at 2.8 A resolution. This antibody and another which has only 56% sequence identity bind to the same epitope with very similar affinities and in the same orientation. One third of the interactions is conserved in the two complexes; a significant proportion of the interactions that differ are established by residues of the H3 complementarity-determining regions (CDR) which adopt distinct conformations in the two antibodies. This demonstrates that there is a definite flexibility in the selection of antibodies that bind to a given epitope, despite the high affinity of their complexes. This flexibility allows the humoral immune response to be redundant, a feature that may be useful in achieving longer lasting protection against evolving viral pathogens. Structural evidence for recognition of a single epitope by two distinct antibodies.,Fleury D, Daniels RS, Skehel JJ, Knossow M, Bizebard T Proteins. 2000 Sep 1;40(4):572-8. PMID:10899782[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences | ||||||||||||||||||
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