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Protein

Hemagglutinin

Gene

HA

Organism
Influenza A virus (strain A/Equine/Kentucky/1/1981)
Status
Reviewed-Annotation score: Annotation score: 4 out of 5-Experimental evidence at transcript leveli

Functioni

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).By similarity

GO - Biological processi

Complete GO annotation...

Keywords - Molecular functioni

Hemagglutinin

Keywords - Biological processi

Clathrin- and caveolin-independent endocytosis of virus by host, Clathrin-mediated endocytosis of virus by host, Fusion of virus membrane with host endosomal membrane, Fusion of virus membrane with host membrane, Host-virus interaction, Viral attachment to host cell, Viral penetration into host cytoplasm, Virus endocytosis by host, Virus entry into host cell

Names & Taxonomyi

Protein namesi
Recommended name:
Hemagglutinin
Cleaved into the following 2 chains:
Gene namesi
Name:HA
OrganismiInfluenza A virus (strain A/Equine/Kentucky/1/1981)
Taxonomic identifieri475467 [NCBI]
Taxonomic lineageiVirusesssRNA virusesssRNA negative-strand virusesOrthomyxoviridaeInfluenzavirus A
Virus hostiAves [TaxID: 8782]
Equus caballus (Horse) [TaxID: 9796]

Subcellular locationi

Topology

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Topological domaini17 – 529513ExtracellularSequence analysisAdd
BLAST
Transmembranei530 – 55021HelicalSequence analysisAdd
BLAST
Topological domaini551 – 56515CytoplasmicSequence analysisAdd
BLAST

GO - Cellular componenti

Complete GO annotation...

Keywords - Cellular componenti

Host cell membrane, Host membrane, Membrane, Viral envelope protein, Virion

PTM / Processingi

Molecule processing

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Signal peptidei1 – 1616Sequence analysisAdd
BLAST
Chaini17 – 343327Hemagglutinin HA1 chainPRO_0000280191Add
BLAST
Chaini345 – 565221Hemagglutinin HA2 chainPRO_0000280192Add
BLAST

Amino acid modifications

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Glycosylationi23 – 231N-linked (GlcNAc...); by hostSequence analysis
Disulfide bondi29 ↔ 481Interchain (between HA1 and HA2 chains)By similarity
Glycosylationi37 – 371N-linked (GlcNAc...); by hostSequence analysis
Glycosylationi53 – 531N-linked (GlcNAc...); by hostSequence analysis
Disulfide bondi67 ↔ 292By similarity
Glycosylationi78 – 781N-linked (GlcNAc...); by hostSequence analysis
Disulfide bondi79 ↔ 91By similarity
Disulfide bondi112 ↔ 154By similarity
Glycosylationi180 – 1801N-linked (GlcNAc...); by hostSequence analysis
Disulfide bondi296 ↔ 320By similarity
Glycosylationi300 – 3001N-linked (GlcNAc...); by hostSequence analysis
Disulfide bondi488 ↔ 492By similarity
Glycosylationi498 – 4981N-linked (GlcNAc...); by hostSequence analysis
Lipidationi554 – 5541S-palmitoyl cysteine; by hostBy similarity
Lipidationi561 – 5611S-palmitoyl cysteine; by hostBy similarity
Lipidationi564 – 5641S-palmitoyl cysteine; by hostBy similarity

Post-translational modificationi

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 Clara cells (By similarity).By similarity
Palmitoylated.By similarity

Sites

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
Sitei344 – 3452Cleavage; by hostBy similarity

Keywords - PTMi

Disulfide bond, Glycoprotein, Lipoprotein, Palmitate

Interactioni

Subunit structurei

Homotrimer of disulfide-linked HA1-HA2.By similarity

Structurei

3D structure databases

ProteinModelPortaliQ82559.
SMRiQ82559. Positions 24-517.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Sequence similaritiesi

Keywords - Domaini

Signal, Transmembrane, Transmembrane helix

Family and domain databases

Gene3Di2.10.77.10. 1 hit.
3.90.20.10. 1 hit.
3.90.209.20. 1 hit.
InterProiIPR008980. Capsid_hemagglutn.
IPR013828. Hemagglutn_HA1_a/b_dom.
IPR013827. Hemagglutn_HA1_b-rbn_dom.
IPR000149. Hemagglutn_influenz_A.
IPR001364. Hemagglutn_influenz_A/B.
IPR013829. Hemagglutn_stalk.
[Graphical view]
PfamiPF00509. Hemagglutinin. 1 hit.
[Graphical view]
PRINTSiPR00330. HEMAGGLUTN1.
PR00329. HEMAGGLUTN12.
SUPFAMiSSF49818. SSF49818. 1 hit.

Sequencei

Sequence statusi: Complete.

Sequence processingi: The displayed sequence is further processed into a mature form.

Q82559-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MKTTIILILL THWVYSQNPT SGNNTATLCL GHHAVANGTL VKTITDDQIE
60 70 80 90 100
VTNATELVQS TSIGKICNNP YRVLDGRNCT LIDAMLGDPH CDVFQYENWD
110 120 130 140 150
LFIERSSAFS NCYPYDIPDY ASLRSIVASS GTLEFTAEGF TWTGVTQNGG
160 170 180 190 200
SGACRRGSAD SFFSRLNWLT KSGNSYPTLN VTMPNNNNFD KLYIWGIHHP
210 220 230 240 250
STNNEQTKLY IQESGRVTVS TKRSQQTIIP NIGSRPWVRG QSGRISIYWT
260 270 280 290 300
IVKPGDILMI NSNGNLVAPR GYFKMRTGKS SVMRSDAPID TCVSECITPN
310 320 330 340 350
GSIPNDKPFQ NVNKVTYGKC PKYIKQNTLK LATGMRNVPE KQIRGIFGAI
360 370 380 390 400
AGFIENGWEG MVDGWYGFRY QNSEGTGQAA DLKSTQAAID QINGKLNRVI
410 420 430 440 450
ERTNEKFHQI EKEFSEVEGR IQDLEKYVED TKIDLWSYNA ELLVALENQH
460 470 480 490 500
TIDLTDAEMN KLFEKTRRQL RENAEDMGGG CFKIYHKCDN ACIGSIRNGT
510 520 530 540 550
YDHYIYRDEA LNNRFQIKGV ELKSGYKDWI LWISFAISCF LICVVLLGFI
560
MWACQKGNIR CNICI
Length:565
Mass (Da):63,633
Last modified:November 1, 1996 - v1
Checksum:iE8412D13945FA424
GO

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
U58195 mRNA. Translation: AAB02560.1.

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
U58195 mRNA. Translation: AAB02560.1.

3D structure databases

ProteinModelPortaliQ82559.
SMRiQ82559. Positions 24-517.
ModBaseiSearch...
MobiDBiSearch...

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Family and domain databases

Gene3Di2.10.77.10. 1 hit.
3.90.20.10. 1 hit.
3.90.209.20. 1 hit.
InterProiIPR008980. Capsid_hemagglutn.
IPR013828. Hemagglutn_HA1_a/b_dom.
IPR013827. Hemagglutn_HA1_b-rbn_dom.
IPR000149. Hemagglutn_influenz_A.
IPR001364. Hemagglutn_influenz_A/B.
IPR013829. Hemagglutn_stalk.
[Graphical view]
PfamiPF00509. Hemagglutinin. 1 hit.
[Graphical view]
PRINTSiPR00330. HEMAGGLUTN1.
PR00329. HEMAGGLUTN12.
SUPFAMiSSF49818. SSF49818. 1 hit.
ProtoNetiSearch...

Publicationsi

  1. "Immunogenicity and efficacy of baculovirus-expressed and DNA-based equine influenza virus hemagglutinin vaccines in mice."
    Olsen C.W., McGregor M.W., Dybdahl-Sissoko N., Schram B.R., Nelson K.M., Lunn D.P., Macklin M.D., Swain W.F., Hinshaw V.S.
    Vaccine 15:1149-1156(1997) [PubMed] [Europe PMC] [Abstract]
    Cited for: NUCLEOTIDE SEQUENCE [MRNA].

Entry informationi

Entry nameiHEMA_I81A2
AccessioniPrimary (citable) accession number: Q82559
Entry historyi
Integrated into UniProtKB/Swiss-Prot: March 6, 2007
Last sequence update: November 1, 1996
Last modified: October 14, 2015
This is version 88 of the entry and version 1 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programViral Protein Annotation Program

Miscellaneousi

Miscellaneous

Major glycoprotein, comprises over 80% of the envelope proteins present in virus particle.
The extent of infection into host organism is determined by HA. Influenza viruses bud from the apical surface of polarized epithelial cells (e.g. bronchial epithelial cells) into lumen of lungs and are therefore usually pneumotropic. The reason is that HA is cleaved by tryptase clara which is restricted to lungs. However, HAs of H5 and H7 pantropic avian viruses subtypes can be cleaved by furin and subtilisin-type enzymes, allowing the virus to grow in other organs than lungs.
The influenza A genome consist of 8 RNA segments. Genetic variation of hemagglutinin and/or neuraminidase genes results in the emergence of new influenza strains. The mechanism of variation can be the result of point mutations or the result of genetic reassortment between segments of two different strains.

Documents

  1. SIMILARITY comments
    Index of protein domains and families

Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into one UniRef entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.