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Q07580 (NRAM_I79A6) Reviewed, UniProtKB/Swiss-Prot

Last modified February 19, 2014. Version 86. 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:
Neuraminidase

EC=3.2.1.18
Gene names
Name:NA
OrganismInfluenza A virus (strain A/Equine/New Market/1979 H3N8)
Taxonomic identifier387226 [NCBI]
Taxonomic lineageVirusesssRNA negative-strand virusesOrthomyxoviridaeInfluenzavirus A
Virus hostAves [TaxID: 8782]
Equus caballus (Horse) [TaxID: 9796]

Protein attributes

Sequence length470 AA.
Sequence statusComplete.
Protein existenceInferred from homology

General annotation (Comments)

Function

Catalyzes the removal of terminal sialic acid residues from viral and cellular glycoconjugates. Cleaves off the terminal sialic acids on the glycosylated HA during virus budding to facilitate virus release. Additionally helps virus spread through the circulation by further removing sialic acids from the cell surface. These cleavages prevent self-aggregation and ensure the efficient spread of the progeny virus from cell to cell. Otherwise, infection would be limited to one round of replication. Described as a receptor-destroying enzyme because it cleaves a terminal sialic acid from the cellular receptors. May facilitate viral invasion of the upper airways by cleaving the sialic acid moities on the mucin of the airway epithelial cells. Likely to plays a role in the budding process through its association with lipid rafts during intracellular transport. May additionally display a raft-association independent effect on budding. Plays a role in the determination of host range restriction on replication and virulence. Sialidase activity in late endosome/lysosome traffic seems to enhance virus replication.

Catalytic activity

Hydrolysis of alpha-(2->3)-, alpha-(2->6)-, alpha-(2->8)- glycosidic linkages of terminal sialic acid residues in oligosaccharides, glycoproteins, glycolipids, colominic acid and synthetic substrates.

Cofactor

Binds 1 calcium ion By similarity.

Enzyme regulation

Inhibited by the neuraminidase inhibitors zanamivir (Relenza) and oseltamivir (Tamiflu). These drugs interfere with the release of progeny virus from infected cells and are effective against all influenza strains. Resistance to neuraminidase inhibitors is quite rare.

Subunit structure

Homotetramer By similarity.

Subcellular location

Virion membrane By similarity. Host apical cell membrane; Single-pass type II membrane protein By similarity. Note: Preferentially accumulates at the apical plasma membrane in infected polarized epithelial cells, which is the virus assembly site. Uses lipid rafts for cell surface transport and apical sorting. In the virion, forms a mushroom-shaped spike on the surface of the membrane By similarity.

Domain

Intact N-terminus is essential for virion morphogenesis. Possess two apical sorting signals, one in the ectodomain, which is likely to be a glycan, and the other in the transmembrane domain. The transmembrane domain also plays a role in lipid raft association By similarity.

Post-translational modification

N-glycosylated By similarity.

Miscellaneous

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 glycosyl hydrolase 34 family.

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Chain1 – 470470Neuraminidase
PRO_0000078699

Regions

Topological domain1 – 66Intravirion Potential
Transmembrane7 – 3529Helical; Signal-anchor for type II membrane protein; Potential
Region11 – 3323Involved in apical transport and lipid raft association By similarity
Region39 – 8850Hypervariable stalk region
Region89 – 470382Head of neuraminidase
Compositional bias439 – 4424Poly-Ser

Sites

Active site1491 Potential
Active site2751 Potential
Active site4021 Potential
Metal binding2921Calcium; via carbonyl oxygen By similarity
Metal binding2961Calcium; via carbonyl oxygen By similarity
Metal binding3221Calcium By similarity
Binding site1161Substrate Potential
Binding site2911Substrate Potential
Binding site3681Substrate Potential

Amino acid modifications

Glycosylation461N-linked (GlcNAc...); by host Potential
Glycosylation541N-linked (GlcNAc...); by host Potential
Glycosylation841N-linked (GlcNAc...); by host Potential
Glycosylation1441N-linked (GlcNAc...); by host Potential
Glycosylation2931N-linked (GlcNAc...); by host Potential
Glycosylation3981N-linked (GlcNAc...); by host Potential
Disulfide bond90 ↔ 417 By similarity
Disulfide bond122 ↔ 127 By similarity
Disulfide bond182 ↔ 229 By similarity
Disulfide bond231 ↔ 236 By similarity
Disulfide bond277 ↔ 290 By similarity
Disulfide bond279 ↔ 288 By similarity
Disulfide bond316 ↔ 335 By similarity
Disulfide bond421 ↔ 446 By similarity

Sequences

Sequence LengthMass (Da)Tools
Q07580 [UniParc].

Last modified February 1, 1995. Version 1.
Checksum: E5795F722E80BC94

FASTA47052,204
        10         20         30         40         50         60 
MNPNQKIIAI GSASLGILIL NVILHVVSII VTVLVLNNNG TGLYCNGTII REYNETVRVE 

        70         80         90        100        110        120 
RITQWYNTNT IEYIERPSNE YYMNNTEPLC EAQGFAPFSK DNGIRIGSRG HVFVIREPFV 

       130        140        150        160        170        180 
SCSPLECRTF FLTQGSLLND KHSNGTVKDR SPYRTFMSVK VGQSPNVYQA RFEAVAWSAT 

       190        200        210        220        230        240 
ACHDGKKWMT VGVTGPDAQA VAVVHYGGVP VDIINSWAGD ILRTQESSCT CIKGDCYWVM 

       250        260        270        280        290        300 
TDGPANRQAK YRIFKAKDGR IIGQTDINFN GGHIEECSCY PNEGKVECVC RDNWTGTNRP 

       310        320        330        340        350        360 
ILVISPDLSY TVGYLCAGIP TDTPRGEDSQ FTGSCTSPLG NQGYGVKGFG FRQGNDVWAG 

       370        380        390        400        410        420 
RTISRTSRLG FEIIKIRNGW TQNSKDQIRK QVIVDNLNWS GYSGSFTLPV ELTKKGCLVP 

       430        440        450        460        470 
CFWVEMIRGK PEETTIWTSS SSIVMCGVDH KIASWSWHDG AILPFDIDKM 

« Hide

References

[1]"Phylogenetic analysis of the N8 neuraminidase gene of influenza A viruses."
Saito T., Kawaoka Y., Webster R.G.
Virology 193:868-876(1993) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC RNA].
[2]"Assembly and budding of influenza virus."
Nayak D.P., Hui E.K., Barman S.
Virus Res. 106:147-165(2004) [PubMed] [Europe PMC] [Abstract]
Cited for: REVIEW.
[3]"Neuraminidase inhibitors for influenza."
Moscona A.
N. Engl. J. Med. 353:1363-1373(2005) [PubMed] [Europe PMC] [Abstract]
Cited for: REVIEW.
[4]"Sialobiology of influenza: molecular mechanism of host range variation of influenza viruses."
Suzuki Y.
Biol. Pharm. Bull. 28:399-408(2005) [PubMed] [Europe PMC] [Abstract]
Cited for: REVIEW.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
L06581 Genomic RNA. Translation: AAA43427.1.

3D structure databases

ProteinModelPortalQ07580.
SMRQ07580. Positions 82-467.
ModBaseSearch...
MobiDBSearch...

Protein family/group databases

CAZyGH34. Glycoside Hydrolase Family 34.

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Family and domain databases

Gene3D2.120.10.10. 1 hit.
InterProIPR001860. Glyco_hydro_34.
IPR011040. Sialidases.
[Graphical view]
PfamPF00064. Neur. 1 hit.
[Graphical view]
SUPFAMSSF50939. SSF50939. 1 hit.
ProtoNetSearch...

Entry information

Entry nameNRAM_I79A6
AccessionPrimary (citable) accession number: Q07580
Entry history
Integrated into UniProtKB/Swiss-Prot: February 1, 1995
Last sequence update: February 1, 1995
Last modified: February 19, 2014
This is version 86 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

Glycosyl hydrolases

Classification of glycosyl hydrolase families and list of entries