B5LBD9 · B5LBD9_9INFA

Function

function

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.
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.

Caution

Lacks conserved residue(s) required for the propagation of feature annotation.

Features

Showing features for site.

TypeIDPosition(s)Description
Site344-345Cleavage; by host

GO annotations

AspectTerm
Cellular Componentapical plasma membrane
Cellular Componenthost cell plasma membrane
Cellular Componentviral envelope
Cellular Componentvirion membrane
Molecular Functionhost cell surface receptor binding
Biological Processclathrin-dependent endocytosis of virus by host cell
Biological Processfusion of virus membrane with host endosome membrane
Biological Processfusion of virus membrane with host plasma membrane
Biological Processviral budding from plasma membrane
Biological Processvirion attachment to host cell

Keywords

Names & Taxonomy

Protein names

Gene names

    • Name
      HA

Organism names

  • Taxonomic identifier
  • Strain
    • A/turkey/England/50-92/91
  • Taxonomic lineage
    Viruses > Riboviria > Orthornavirae > Negarnaviricota > Polyploviricotina > Insthoviricetes > Articulavirales > Orthomyxoviridae > Alphainfluenzavirus > Alphainfluenzavirus influenzae > Influenza A virus

Accessions

  • Primary accession
    B5LBD9

Proteomes

Subcellular Location

Host apical cell membrane
; Single-pass type I membrane protein
Virion membrane
; Single-pass type I membrane protein
Note: Targeted to the apical plasma membrane in epithelial polarized cells through a signal present in the transmembrane domain. Associated with glycosphingolipid- and cholesterol-enriched detergent-resistant lipid rafts.

Features

Showing features for transmembrane.

TypeIDPosition(s)Description
Transmembrane531-553Helical

Keywords

PTM/Processing

Features

Showing features for disulfide bond, chain, lipidation.

TypeIDPosition(s)Description
Disulfide bond58↔290
Disulfide bond71↔83
Disulfide bond106↔151
Disulfide bond294↔318
ChainPRO_5023334645345-566Hemagglutinin HA2 chain
Disulfide bond488↔492
Lipidation555S-palmitoyl cysteine; by host
Lipidation562S-palmitoyl cysteine; by host
Lipidation565S-palmitoyl cysteine; by host

Post-translational modification

In natural infection, inactive HA is matured into HA1 and HA2 outside the cell by one or more trypsin-like, arginine-specific endoprotease secreted by the bronchial epithelial cells. One identified protease that may be involved in this process is secreted in lungs by club cells.
Palmitoylated.

Keywords

Interaction

Subunit

Homotrimer of disulfide-linked HA1-HA2.

Family & Domains

Features

Showing features for coiled coil.

TypeIDPosition(s)Description
Coiled coil400-434

Sequence similarities

Belongs to the influenza viruses hemagglutinin family.

Keywords

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    566
  • Mass (Da)
    63,731
  • Last updated
    2008-10-14 v1
  • Checksum
    21F214D408207F68
MEKIVLLLAIVSLVKSDQICIGYHANNSTEQVDTIMEKNVTVTHAQDILEKTHNGKLCSLNGVKPLILRDCSVAGWLLGNPMCDEFLNVPEWSYIVEKDNPVNGLCYPGDFNDYEELKHLLSSTNHFEKIQIIPRSSWSNHDASSGVSSACPYNGRSSFFRNVVWLIKKNNTYPTIKRSYSNTNQEDLLVLWGIHHPNDAAEQTKLYQNPTTYVSVGTSTLNQRSVPAIATRPKVNGQSGRMEFFWTILKPNDAINFESNGNFIAPEYAYKIVKKGDSAIMKSGLEYGNCNTKCQTPMGAINSSMPLHNIHPLTIGECPKYVKSDRLVLATGPRNVPQRKRKTRGLFGAIAGFIEGGWQGMVDGWYGYHHSNEQGSGYAADKESTQKAIDGITNKVNSIIDKMNTQFEAVGKEFNNLERRIENLNKKMEDGFLDVWTYNAELLVHMENERTLDFHDSNVKNLYDKVRLQLRDNAKELGNGCFEFYHKCDNECMESVKNGTYNYPQYSEEARLNREEISGVKLESMGTYQILSIYSTVASSLALAIMIAGLSFWMCSNGSLQCRICI

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
EU636692
EMBL· GenBank· DDBJ
ACF40968.1
EMBL· GenBank· DDBJ
Viral cRNA

Similar Proteins

Disclaimer

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