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P03481 (NRAM_I78A0) Reviewed, UniProtKB/Swiss-Prot

Last modified February 19, 2014. Version 87. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (2) | Third-party data text xml rdf/xml gff fasta
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Names and origin

Protein namesRecommended name:
Neuraminidase

EC=3.2.1.18
Gene names
Name:NA
OrganismInfluenza A virus (strain A/Black duck/Australia/702/1978 H3N8)
Taxonomic identifier385637 [NCBI]
Taxonomic lineageVirusesssRNA negative-strand virusesOrthomyxoviridaeInfluenzavirus A
Virus hostAves [TaxID: 8782]

Protein attributes

Sequence length102 AA.
Sequence statusFragment.
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 – ›102›102Neuraminidase
PRO_0000078677

Regions

Topological domain1 – 66Intravirion Potential
Transmembrane7 – 3529Helical; Signal-anchor for type II membrane protein; Potential
Topological domain36 – ›102›67Virion surface Potential
Region11 – 3323Involved in apical transport and lipid raft association By similarity
Region37 – 8852Hypervariable stalk region
Region89 – ›102›14Head of neuraminidase

Amino acid modifications

Glycosylation461N-linked (GlcNAc...); by host Potential
Glycosylation541N-linked (GlcNAc...); by host Potential
Glycosylation841N-linked (GlcNAc...); by host Potential

Experimental info

Non-terminal residue1021

Sequences

Sequence LengthMass (Da)Tools
P03481 [UniParc].

Last modified July 21, 1986. Version 1.
Checksum: 22D9F38E8660AD66

FASTA10211,626
        10         20         30         40         50         60 
MNPNQKIITI GSVSLGLVCL DILLHIISIT ITVLGLHKNG KQRRCNETVI REDNETVRIE 

        70         80         90        100 
KVTQWHNTNV IEYIEKLEGD HFMNNTEPLC HAKGFALFSK DN 

« Hide

References

[1]"Variation in the membrane-insertion and 'stalk' sequences in eight subtypes of influenza type A virus neuraminidase."
Blok J., Air G.M.
Biochemistry 21:4001-4007(1982) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC RNA].
[2]"Sequence variation at the 3' end of the neuraminidase gene from 39 influenza type A viruses."
Blok J., Air G.M.
Virology 121:211-229(1982) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE.
[3]"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.
[4]"Neuraminidase inhibitors for influenza."
Moscona A.
N. Engl. J. Med. 353:1363-1373(2005) [PubMed] [Europe PMC] [Abstract]
Cited for: REVIEW.
[5]"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
V01097 Unassigned RNA. Translation: CAA24280.1.
K01002 Genomic RNA. Translation: AAA43359.1.

3D structure databases

ModBaseSearch...
MobiDBSearch...

Protein family/group databases

CAZyGH34. Glycoside Hydrolase Family 34.

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Family and domain databases

InterProIPR001860. Glyco_hydro_34.
[Graphical view]
PfamPF00064. Neur. 1 hit.
[Graphical view]
ProtoNetSearch...

Entry information

Entry nameNRAM_I78A0
AccessionPrimary (citable) accession number: P03481
Entry history
Integrated into UniProtKB/Swiss-Prot: July 21, 1986
Last sequence update: July 21, 1986
Last modified: February 19, 2014
This is version 87 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