Skip Header

You are using a version of browser that may not display all the features of this website. Please consider upgrading your browser.
Protein

Hemagglutinin

Gene

HA

Organism
Influenza A virus (strain A/Equine/Jillin/1/1989 H3N8)
Status
Reviewed-Annotation score: Annotation score: 4 out of 5-Experimental evidence at protein 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/Jillin/1/1989 H3N8)
Taxonomic identifieri385585 [NCBI]
Taxonomic lineageiVirusesssRNA virusesssRNA negative-strand virusesOrthomyxoviridaeInfluenzavirus A
Virus hostiAves [TaxID: 8782]
Equus caballus (Horse) [TaxID: 9796]

Subcellular locationi

Topology

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Topological domaini24 – 535ExtracellularSequence analysisAdd BLAST512
Transmembranei536 – 556HelicalSequence analysisAdd BLAST21
Topological domaini557 – 571CytoplasmicSequence analysisAdd BLAST15

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)DescriptionActionsGraphical viewLength
Signal peptidei1 – 21Sequence analysisAdd BLAST21
ChainiPRO_000028018922 – 349Hemagglutinin HA1 chainAdd BLAST328
ChainiPRO_0000280190351 – 571Hemagglutinin HA2 chainAdd BLAST221

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Glycosylationi29N-linked (GlcNAc...); by hostSequence analysis1
Disulfide bondi35 ↔ 487Interchain (between HA1 and HA2 chains)By similarity
Glycosylationi43N-linked (GlcNAc...); by hostSequence analysis1
Glycosylationi59N-linked (GlcNAc...); by hostSequence analysis1
Disulfide bondi73 ↔ 298By similarity
Glycosylationi84N-linked (GlcNAc...); by hostSequence analysis1
Disulfide bondi85 ↔ 97By similarity
Disulfide bondi118 ↔ 160By similarity
Glycosylationi186N-linked (GlcNAc...); by hostSequence analysis1
Disulfide bondi302 ↔ 326By similarity
Glycosylationi306N-linked (GlcNAc...); by hostSequence analysis1
Disulfide bondi494 ↔ 498By similarity
Glycosylationi504N-linked (GlcNAc...); by hostSequence analysis1
Lipidationi560S-palmitoyl cysteine; by hostBy similarity1
Lipidationi567S-palmitoyl cysteine; by hostBy similarity1
Lipidationi570S-palmitoyl cysteine; by hostBy similarity1

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)DescriptionActionsGraphical viewLength
Sitei350 – 351Cleavage; by hostBy similarity2

Keywords - PTMi

Disulfide bond, Glycoprotein, Lipoprotein, Palmitate

Interactioni

Subunit structurei

Homotrimer of disulfide-linked HA1-HA2.By similarity

Structurei

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
1HXYX-ray2.60C327-339[»]
2IPKX-ray2.30C327-339[»]
2XN9X-ray2.30F327-339[»]
ProteinModelPortaliQ03909.
SMRiQ03909.
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.

Q03909-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MLSLIMRTVI ALSYIFCLAF GQGLPWNDNN TATLCLGHHA VPNGTIVKTI
60 70 80 90 100
TDDQIEVTNA TELVQSSSTG KICNNPHRIL DGGNCTLIDA LLGDPHCNVF
110 120 130 140 150
QYETWDLFVE RTNAFSNCYP YDVPDYASLR SIVASSGTLE FFAESFTWTG
160 170 180 190 200
VTQNGGSSAC KRGTASSFFS RLNWLTKSGN AYPLLNVTMP NNDNFDKLYI
210 220 230 240 250
WGVHHPSTNQ EQTELYVQAS GRVTVSTRKS QQTVIPNIGS RPWVRGQSGR
260 270 280 290 300
VSIYWTIVKP GDVLVINSNG NLIAPRGYFK VRTGKSSIMR SDAPIDTCIS
310 320 330 340 350
ECITPNGSIP NDKPFQNVNK ITYGACPKYV KQNTLKLATG MRNVPEKQIR
360 370 380 390 400
GIFGAIAGFI ENGWEGMIDG WYGFRHQNSE GTGQAADLKS TQAALDQING
410 420 430 440 450
KLNRVIEKTN EKFHQIEKEF SEVEGRIQDL EKYVEDTKID LWSYNAELLV
460 470 480 490 500
ALENQHTIDL TDSEMNKLFE KTRRQLRENA EDMGNGCFKI YHNCDNACIE
510 520 530 540 550
SIRNGTYDHN IYRDEALNNR FQIKGVELKS GYKDWILWIS FAISCFLLCV
560 570
VLLGFIMWAC QKGNIRCNIC F
Length:571
Mass (Da):64,105
Last modified:November 1, 1996 - v1
Checksum:i718DAA0F291CE349
GO

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
M65018 Genomic RNA. Translation: AAA43151.1.

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
M65018 Genomic RNA. Translation: AAA43151.1.

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
1HXYX-ray2.60C327-339[»]
2IPKX-ray2.30C327-339[»]
2XN9X-ray2.30F327-339[»]
ProteinModelPortaliQ03909.
SMRiQ03909.
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...

Entry informationi

Entry nameiHEMA_I89A7
AccessioniPrimary (citable) accession number: Q03909
Entry historyi
Integrated into UniProtKB/Swiss-Prot: March 6, 2007
Last sequence update: November 1, 1996
Last modified: November 2, 2016
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.

Keywords - Technical termi

3D-structure

Documents

  1. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references
  2. 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.