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O56140 (HEMA_I97A1) Reviewed, UniProtKB/Swiss-Prot

Last modified February 19, 2014. Version 89. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (1) | Third-party data text xml rdf/xml gff fasta
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Protein attributes

Sequence length568 AA.
Sequence statusComplete.
Sequence processingThe displayed sequence is further processed into a mature form.
Protein existenceEvidence at transcript 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 speptide. Several trimers are required to form a competent fusion pore.

Subunit structure

Homotrimer of disulfide-linked HA1-HA2.

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.

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.

Ontologies

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Signal peptide1 – 1616 Potential
Chain17 – 338322Hemagglutinin HA1 chain
PRO_0000043412
Propeptide339 – 3468Connecting peptide
PRO_0000392214
Chain347 – 568222Hemagglutinin HA2 chain
PRO_0000043413

Regions

Topological domain17 – 531515Extracellular Potential
Transmembrane532 – 55221Helical; Potential
Topological domain553 – 56816Cytoplasmic Potential

Sites

Site346 – 3472Cleavage; by host

Amino acid modifications

Lipidation5571S-palmitoyl cysteine; by host By similarity
Lipidation5641S-palmitoyl cysteine; by host By similarity
Lipidation5671S-palmitoyl cysteine; by host By similarity
Glycosylation261N-linked (GlcNAc...); by host Potential
Glycosylation271N-linked (GlcNAc...); by host Potential
Glycosylation391N-linked (GlcNAc...); by host Potential
Glycosylation1811N-linked (GlcNAc...); by host Potential
Glycosylation3021N-linked (GlcNAc...); by host Potential
Glycosylation5001N-linked (GlcNAc...); by host Potential
Disulfide bond20 ↔ 483Interchain (between HA1 and HA2 chains) By similarity
Disulfide bond58 ↔ 290 By similarity
Disulfide bond71 ↔ 83 By similarity
Disulfide bond106 ↔ 151 By similarity
Disulfide bond294 ↔ 318 By similarity
Disulfide bond490 ↔ 494 By similarity

Experimental info

Sequence conflict31K → R in AAC40508. Ref.1
Sequence conflict1941I → V in AAC40508. Ref.1
Sequence conflict379 – 3813GYA → CYS in AAC40508. Ref.1

Sequences

Sequence LengthMass (Da)Tools
O56140 [UniParc].

Last modified January 24, 2006. Version 2.
Checksum: D99BD1729B730A40

FASTA56864,277
        10         20         30         40         50         60 
MEKTVLLLAT VSLVKSDQIC IGYHANNSTE QVDTIMEKNV TVTHAQDILE RTHNGKLCDL 

        70         80         90        100        110        120 
NGVKPLILRD CSVAGWLLGN PMCDEFINVP EWSYIVEKAS PANDLCYPGN FNDYEELKHL 

       130        140        150        160        170        180 
LSRINHFEKI QIIPKSSWSN HDASSGVSSA CPYLGRSSFF RNVVWLIKKN SAYPTIKRSY 

       190        200        210        220        230        240 
NNTNQEDLLV LWGIHHPNDA AEQTKLYQNP TTYISVGTST LNQRLVPEIA TRPKVNGQSG 

       250        260        270        280        290        300 
RMEFFWTILK PNDAINFESN GNFIAPEYAY KIVKKGDSTI MKSELEYGNC NTKCQTPMGA 

       310        320        330        340        350        360 
INSSMPFHNI HPLTIGECPK YVKSNRLVLA TGLRNTPQRE RRRKKRGLFG AIAGFIEGGW 

       370        380        390        400        410        420 
QGMVDGWYGY HHSNEQGSGY AADKESTQKA IDGVTNKVNS IINKMNTQFE AVGREFNNLE 

       430        440        450        460        470        480 
RRIENLNKKM EDGFLDVWTY NAELLVLMEN ERTLDFHDSN VKNLYDKVRL QLRDNAKELG 

       490        500        510        520        530        540 
NGCFEFYHKC DNECMESVKN GTYDYPQYSE EARLNREEIS GVKLESMGTY QILSIYSTVA 

       550        560 
SSLALAIMVA GLSLWMCSNG SLQCRICI 

« Hide

References

[1]"Human influenza A H5N1 virus related to a highly pathogenic avian influenza virus."
Claas E.C.J., Osterhaus A.D., van Beek R., De Jong J.C., Rimmelzwaan G.F., Senne D.A., Krauss S., Shortridge K.F., Webster R.G.
Lancet 351:472-477(1998) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [MRNA].
[2]"Comparisons of highly virulent H5N1 influenza A viruses isolated from humans and chickens from Hong Kong."
Suarez D.L., Perdue M.L., Cox N., Rowe T., Bender C., Huang J., Swayne D.E.
J. Virol. 72:6678-6688(1998) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC RNA].
[3]"Characterization of an avian influenza A (H5N1) virus isolated from a child with a fatal respiratory illness."
Subbarao K., Klimov A., Katz J., Regnery H., Lim W., Hall H., Perdue M., Swayne D., Bender C., Huang J., Hemphill M., Rowe T., Shaw M., Xu X., Fukuda K., Cox N.
Science 279:393-396(1998) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC RNA] OF 17-568.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
AF028709 mRNA. Translation: AAC40508.1.
AF046088 Genomic RNA. Translation: AAC32088.1.
AF036356 Genomic RNA. Translation: AAC34263.1.

3D structure databases

ProteinModelPortalO56140.
SMRO56140. Positions 17-337, 347-520.
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_I97A1
AccessionPrimary (citable) accession number: O56140
Secondary accession number(s): O56262, Q9WAA0
Entry history
Integrated into UniProtKB/Swiss-Prot: December 6, 2005
Last sequence update: January 24, 2006
Last modified: February 19, 2014
This is version 89 of the entry and version 2 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