ID Q67045_9INFA Unreviewed; 131 AA. AC Q67045; DT 01-NOV-1996, integrated into UniProtKB/TrEMBL. DT 01-NOV-1996, sequence version 1. DT 08-NOV-2023, entry version 118. DE SubName: Full=Hemagglutinin {ECO:0000313|EMBL:BAA02771.1}; DE Flags: Fragment; GN Name=HA {ECO:0000313|EMBL:BAA02771.1}; OS Influenza A virus (A/Adachi/2/1957(H2N2)). OC Viruses; Riboviria; Orthornavirae; Negarnaviricota; Polyploviricotina; OC Insthoviricetes; Articulavirales; Orthomyxoviridae; Alphainfluenzavirus; OC Alphainfluenzavirus influenzae; Influenza A virus. OX NCBI_TaxID=516994 {ECO:0000313|EMBL:BAA02771.1}; RN [1] {ECO:0000313|EMBL:BAA02771.1} RP NUCLEOTIDE SEQUENCE. RC STRAIN=A/Adachi/2/57 {ECO:0000313|EMBL:BAA02771.1}; RX PubMed=7421990; DOI=10.1038/287301a0; RA Gething M.J., Bye J., Skehel J., Waterfield M.; RT "Cloning and DNA sequence of double-stranded copies of haemagglutinin genes RT from H2 and H3 strains elucidates antigenic shift and drift in human RT influenza virus."; RL Nature 287:301-306(1980). RN [2] {ECO:0000313|EMBL:BAA02771.1} RP NUCLEOTIDE SEQUENCE. RC STRAIN=A/Adachi/2/57 {ECO:0000313|EMBL:BAA02771.1}; RX PubMed=7682624; RA Okuno Y., Isegawa Y., Sasao F., Ueda S.; RT "A common neutralizing epitope conserved between the hemagglutinins of RT influenza A virus H1 and H2 strains."; RL J. Virol. 67:2552-2558(1993). CC -!- FUNCTION: Binds to sialic acid-containing receptors on the cell CC surface, bringing about the attachment of the virus particle to the CC cell. This attachment induces virion internalization of about two third CC of the virus particles through clathrin-dependent endocytosis and about CC one third through a clathrin- and caveolin-independent pathway. Plays a CC major role in the determination of host range restriction and CC virulence. Class I viral fusion protein. Responsible for penetration of CC the virus into the cell cytoplasm by mediating the fusion of the CC membrane of the endocytosed virus particle with the endosomal membrane. CC Low pH in endosomes induces an irreversible conformational change in CC HA2, releasing the fusion hydrophobic peptide. Several trimers are CC required to form a competent fusion pore. CC {ECO:0000256|RuleBase:RU003324}. CC -!- SUBUNIT: Homotrimer of disulfide-linked HA1-HA2. CC {ECO:0000256|RuleBase:RU003324}. CC -!- SUBCELLULAR LOCATION: Cell membrane {ECO:0000256|ARBA:ARBA00004251}; CC Single-pass type I membrane protein {ECO:0000256|ARBA:ARBA00004251}. CC Membrane {ECO:0000256|ARBA:ARBA00004479}; Single-pass type I membrane CC protein {ECO:0000256|ARBA:ARBA00004479}. CC -!- SIMILARITY: Belongs to the influenza viruses hemagglutinin family. CC {ECO:0000256|RuleBase:RU003324}. CC --------------------------------------------------------------------------- CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms CC Distributed under the Creative Commons Attribution (CC BY 4.0) License CC --------------------------------------------------------------------------- DR EMBL; D13576; BAA02771.1; -; Genomic_RNA. DR GO; GO:0020002; C:host cell plasma membrane; IEA:UniProtKB-KW. DR GO; GO:0005886; C:plasma membrane; IEA:UniProtKB-SubCell. DR GO; GO:0019031; C:viral envelope; IEA:UniProtKB-KW. DR GO; GO:0046789; F:host cell surface receptor binding; IEA:InterPro. DR GO; GO:0039654; P:fusion of virus membrane with host endosome membrane; IEA:UniProtKB-KW. DR GO; GO:0019064; P:fusion of virus membrane with host plasma membrane; IEA:InterPro. DR GO; GO:0046718; P:viral entry into host cell; IEA:UniProtKB-KW. DR GO; GO:0019062; P:virion attachment to host cell; IEA:UniProtKB-KW. DR Gene3D; 3.90.20.10; -; 1. DR InterPro; IPR008980; Capsid_hemagglutn. DR InterPro; IPR001364; Hemagglutn_influenz_A/B. DR InterPro; IPR000386; Hemagglutn_influenz_B. DR Pfam; PF00509; Hemagglutinin; 1. DR PRINTS; PR00329; HEMAGGLUTN12. DR PRINTS; PR00331; HEMAGGLUTN2. DR SUPFAM; SSF58064; Influenza hemagglutinin (stalk); 1. DR SUPFAM; SSF49818; Viral protein domain; 1. PE 3: Inferred from homology; KW Disulfide bond {ECO:0000256|ARBA:ARBA00023157}; KW Fusion of virus membrane with host endosomal membrane KW {ECO:0000256|ARBA:ARBA00022510}; KW Fusion of virus membrane with host membrane KW {ECO:0000256|ARBA:ARBA00022506}; KW Glycoprotein {ECO:0000256|ARBA:ARBA00023180}; KW Hemagglutinin {ECO:0000256|ARBA:ARBA00022546, KW ECO:0000256|RuleBase:RU003324}; KW Host cell membrane {ECO:0000256|ARBA:ARBA00022511}; KW Host membrane {ECO:0000256|ARBA:ARBA00022870}; KW Host-virus interaction {ECO:0000256|ARBA:ARBA00022581}; KW Membrane {ECO:0000256|ARBA:ARBA00023136}; KW Viral attachment to host cell {ECO:0000256|ARBA:ARBA00022804}; KW Viral envelope protein {ECO:0000256|ARBA:ARBA00022879, KW ECO:0000256|RuleBase:RU003324}; KW Viral penetration into host cytoplasm {ECO:0000256|ARBA:ARBA00022595}; KW Virion {ECO:0000256|ARBA:ARBA00022844}; KW Virus entry into host cell {ECO:0000256|ARBA:ARBA00023296}. FT NON_TER 1 FT /evidence="ECO:0000313|EMBL:BAA02771.1" FT NON_TER 131 FT /evidence="ECO:0000313|EMBL:BAA02771.1" SQ SEQUENCE 131 AA; 14550 MW; 243DFC623E7F2952 CRC64; NTTLPFHNVH PLTIGECPKY VKSEKLVLAT GLRNVPQIES RGLFGAIAGF IEGGWQGMVD GWYGYHHSND QGSGYAADKE STQKAFDGIT NKVNSVIEKM NTQFEAVGKE FGNLERRLEN LNKKMEDGFL D //