1ha0
HEMAGGLUTININ PRECURSOR HA0
Structural highlights
FunctionHEMA_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 membrane fusion potential of influenza HA, like many viral membrane-fusion glycoproteins, is generated by proteolytic cleavage of a biosynthetic precursor. The three-dimensional structure of ectodomain of the precursor HA0 has been determined and compared with that of cleaved HA. The cleavage site is a prominent surface loop adjacent to a novel cavity; cleavage results in structural rearrangements in which the nonpolar amino acids near the new amino terminus bury ionizable residues in the cavity that are implicated in the low-pH-induced conformational change. Amino acid insertions at the cleavage site in HAs of virulent avian viruses and those of viruses isolated from the recent severe outbreak of influenza in humans in Hong Kong would extend this surface loop, facilitating intracellular cleavage. Structure of the hemagglutinin precursor cleavage site, a determinant of influenza pathogenicity and the origin of the labile conformation.,Chen J, Lee KH, Steinhauer DA, Stevens DJ, Skehel JJ, Wiley DC Cell. 1998 Oct 30;95(3):409-17. PMID:9814710[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences | ||||||||||||||||||||
