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Q03909 (HEMA_I89A7) Reviewed, UniProtKB/Swiss-Prot

Last modified February 19, 2014. Version 79. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (2) | Third-party data text xml rdf/xml gff fasta
to top of pageNames·Attributes·General annotation·Ontologies·Sequence annotation·Sequences·References·Cross-refs·Entry info·DocumentsCustomize order

Names and origin

Protein namesRecommended name:
Hemagglutinin

Cleaved into the following 2 chains:

  1. Hemagglutinin HA1 chain
  2. Hemagglutinin HA2 chain
Gene names
Name:HA
OrganismInfluenza A virus (strain A/Equine/Jillin/1/1989 H3N8)
Taxonomic identifier385585 [NCBI]
Taxonomic lineageVirusesssRNA negative-strand virusesOrthomyxoviridaeInfluenzavirus A
Virus hostAves [TaxID: 8782]
Equus caballus (Horse) [TaxID: 9796]

Protein attributes

Sequence length571 AA.
Sequence statusComplete.
Sequence processingThe displayed sequence is further processed into a mature form.
Protein existenceEvidence at protein level

General annotation (Comments)

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 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.

Subunit structure

Homotrimer of disulfide-linked HA1-HA2 By similarity.

Subcellular location

Virion membrane; Single-pass type I membrane protein Potential. Host apical cell 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 By similarity.

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 Clara cells By similarity.

Palmitoylated By similarity.

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.

Sequence similarities

Belongs to the influenza viruses hemagglutinin family.

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Signal peptide1 – 2121 Potential
Chain22 – 349328Hemagglutinin HA1 chain
PRO_0000280189
Chain351 – 571221Hemagglutinin HA2 chain
PRO_0000280190

Regions

Topological domain24 – 535512Extracellular Potential
Transmembrane536 – 55621Helical; Potential
Topological domain557 – 57115Cytoplasmic Potential

Sites

Site350 – 3512Cleavage; by host By similarity

Amino acid modifications

Lipidation5601S-palmitoyl cysteine; by host By similarity
Lipidation5671S-palmitoyl cysteine; by host By similarity
Lipidation5701S-palmitoyl cysteine; by host By similarity
Glycosylation291N-linked (GlcNAc...); by host Potential
Glycosylation431N-linked (GlcNAc...); by host Potential
Glycosylation591N-linked (GlcNAc...); by host Potential
Glycosylation841N-linked (GlcNAc...); by host Potential
Glycosylation1861N-linked (GlcNAc...); by host Potential
Glycosylation3061N-linked (GlcNAc...); by host Potential
Glycosylation5041N-linked (GlcNAc...); by host Potential
Disulfide bond35 ↔ 487Interchain (between HA1 and HA2 chains) By similarity
Disulfide bond73 ↔ 298 By similarity
Disulfide bond85 ↔ 97 By similarity
Disulfide bond118 ↔ 160 By similarity
Disulfide bond302 ↔ 326 By similarity
Disulfide bond494 ↔ 498 By similarity

Sequences

Sequence LengthMass (Da)Tools
Q03909 [UniParc].

Last modified November 1, 1996. Version 1.
Checksum: 718DAA0F291CE349

FASTA57164,105
        10         20         30         40         50         60 
MLSLIMRTVI ALSYIFCLAF GQGLPWNDNN TATLCLGHHA VPNGTIVKTI TDDQIEVTNA 

        70         80         90        100        110        120 
TELVQSSSTG KICNNPHRIL DGGNCTLIDA LLGDPHCNVF QYETWDLFVE RTNAFSNCYP 

       130        140        150        160        170        180 
YDVPDYASLR SIVASSGTLE FFAESFTWTG VTQNGGSSAC KRGTASSFFS RLNWLTKSGN 

       190        200        210        220        230        240 
AYPLLNVTMP NNDNFDKLYI WGVHHPSTNQ EQTELYVQAS GRVTVSTRKS QQTVIPNIGS 

       250        260        270        280        290        300 
RPWVRGQSGR VSIYWTIVKP GDVLVINSNG NLIAPRGYFK VRTGKSSIMR SDAPIDTCIS 

       310        320        330        340        350        360 
ECITPNGSIP NDKPFQNVNK ITYGACPKYV KQNTLKLATG MRNVPEKQIR GIFGAIAGFI 

       370        380        390        400        410        420 
ENGWEGMIDG WYGFRHQNSE GTGQAADLKS TQAALDQING KLNRVIEKTN EKFHQIEKEF 

       430        440        450        460        470        480 
SEVEGRIQDL EKYVEDTKID LWSYNAELLV ALENQHTIDL TDSEMNKLFE KTRRQLRENA 

       490        500        510        520        530        540 
EDMGNGCFKI YHNCDNACIE SIRNGTYDHN IYRDEALNNR FQIKGVELKS GYKDWILWIS 

       550        560        570 
FAISCFLLCV VLLGFIMWAC QKGNIRCNIC F 

« Hide

References

[1]"Emergence of a new influenza A virus in horses from avian sources."
Guo Y., Wang M.G., Kawaoka Y., Gorman O.T., Ito T., Webster R.G.
Submitted (JUN-1991) to the EMBL/GenBank/DDBJ databases
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC RNA].
+Additional computationally mapped references.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
M65018 Genomic RNA. Translation: AAA43151.1.

3D structure databases

PDBe
RCSB PDB
PDBj
EntryMethodResolution (Å)ChainPositionsPDBsum
2IPKX-ray2.30C327-339[»]
2XN9X-ray2.30F327-339[»]
ProteinModelPortalQ03909.
SMRQ03909. Positions 30-523.
ModBaseSearch...
MobiDBSearch...

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Family and domain databases

Gene3D2.10.77.10. 1 hit.
3.90.20.10. 1 hit.
3.90.209.20. 1 hit.
InterProIPR008980. 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]
PfamPF00509. Hemagglutinin. 1 hit.
[Graphical view]
PRINTSPR00330. HEMAGGLUTN1.
PR00329. HEMAGGLUTN12.
SUPFAMSSF49818. SSF49818. 1 hit.
ProtoNetSearch...

Entry information

Entry nameHEMA_I89A7
AccessionPrimary (citable) accession number: Q03909
Entry history
Integrated into UniProtKB/Swiss-Prot: March 6, 2007
Last sequence update: November 1, 1996
Last modified: February 19, 2014
This is version 79 of the entry and version 1 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programViral Protein Annotation Program

Relevant documents

SIMILARITY comments

Index of protein domains and families

PDB cross-references

Index of Protein Data Bank (PDB) cross-references