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Protein

Neuraminidase

Gene

NA

Organism
Influenza A virus (strain A/Port Chalmers/1/1973 H3N2)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Protein inferred from homologyi

Functioni

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 activityi

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.

Cofactori

Ca2+By similarityNote: Binds 1 Ca2+ ion per subunit.By similarity

Enzyme regulationi

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.

Sites

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Binding sitei118SubstrateBy similarity1
Active sitei151Proton donor/acceptorBy similarity1
Binding sitei152SubstrateBy similarity1
Binding sitei292SubstrateBy similarity1
Metal bindingi293Calcium; via carbonyl oxygenBy similarity1
Metal bindingi297Calcium; via carbonyl oxygenBy similarity1
Metal bindingi324CalciumBy similarity1
Binding sitei371SubstrateBy similarity1
Active sitei406NucleophileBy similarity1

GO - Molecular functioni

GO - Biological processi

Complete GO annotation...

Keywords - Molecular functioni

Glycosidase, Hydrolase

Keywords - Ligandi

Calcium, Metal-binding

Protein family/group databases

CAZyiGH34. Glycoside Hydrolase Family 34.

Names & Taxonomyi

Protein namesi
Recommended name:
Neuraminidase (EC:3.2.1.18)
Gene namesi
Name:NA
OrganismiInfluenza A virus (strain A/Port Chalmers/1/1973 H3N2)
Taxonomic identifieri385624 [NCBI]
Taxonomic lineageiVirusesssRNA virusesssRNA negative-strand virusesOrthomyxoviridaeInfluenzavirus A
Virus hostiAves [TaxID: 8782]
Cetacea (whales) [TaxID: 9721]
Homo sapiens (Human) [TaxID: 9606]
Phocidae (true seals) [TaxID: 9709]
Sus scrofa (Pig) [TaxID: 9823]
Proteomesi
  • UP000007791 Componenti: Genome

Subcellular locationi

  • Virion membrane By similarity
  • Host apical cell membrane By similarity; 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).By similarity

Topology

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Topological domaini1 – 9IntravirionSequence analysis9
Transmembranei10 – 30Helical; Signal-anchor for type II membrane proteinSequence analysisAdd BLAST21
Topological domaini31 – 469Virion surfaceSequence analysisAdd BLAST439

GO - Cellular componenti

Complete GO annotation...

Keywords - Cellular componenti

Host cell membrane, Host membrane, Membrane, Virion

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
ChainiPRO_00002801471 – 469NeuraminidaseAdd BLAST469

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Glycosylationi61N-linked (GlcNAc...); by hostSequence analysis1
Glycosylationi70N-linked (GlcNAc...); by hostSequence analysis1
Glycosylationi86N-linked (GlcNAc...); by hostSequence analysis1
Disulfide bondi92 ↔ 417By similarity
Disulfide bondi124 ↔ 129By similarity
Glycosylationi146N-linked (GlcNAc...); by hostSequence analysis1
Disulfide bondi175 ↔ 193By similarity
Disulfide bondi183 ↔ 230By similarity
Glycosylationi200N-linked (GlcNAc...); by hostSequence analysis1
Disulfide bondi232 ↔ 237By similarity
Glycosylationi234N-linked (GlcNAc...); by hostSequence analysis1
Disulfide bondi278 ↔ 291By similarity
Disulfide bondi280 ↔ 289By similarity
Disulfide bondi318 ↔ 337By similarity
Glycosylationi402N-linked (GlcNAc...); by hostSequence analysis1
Disulfide bondi421 ↔ 447By similarity

Post-translational modificationi

N-glycosylated.By similarity

Keywords - PTMi

Disulfide bond, Glycoprotein

Interactioni

Subunit structurei

Homotetramer.By similarity

Structurei

3D structure databases

ProteinModelPortaliQ1PUD6.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Region

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Regioni11 – 33Involved in apical transport and lipid raft associationBy similarityAdd BLAST23
Regioni36 – 90Hypervariable stalk regionBy similarityAdd BLAST55
Regioni91 – 469Head of neuraminidaseBy similarityAdd BLAST379
Regioni276 – 277Substrate bindingBy similarity2

Domaini

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).By similarity

Sequence similaritiesi

Belongs to the glycosyl hydrolase 34 family.Curated

Keywords - Domaini

Signal-anchor, Transmembrane, Transmembrane helix

Family and domain databases

CDDicd15483. Influenza_NA. 1 hit.
Gene3Di2.120.10.10. 1 hit.
InterProiIPR001860. Glyco_hydro_34.
IPR033654. Sialidase_Influenza_A/B.
IPR011040. Sialidases.
[Graphical view]
PfamiPF00064. Neur. 1 hit.
[Graphical view]
SUPFAMiSSF50939. SSF50939. 1 hit.

Sequencei

Sequence statusi: Complete.

Q1PUD6-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MNPNQKIITI GSVSLIIATI CFLMQIAILV TTVTLHFKQY ECDSPANNQV
60 70 80 90 100
MPCEPIIIER NITEIVYLTN TTIEKEICPK LVEYRNWSKP QCKITGFAPF
110 120 130 140 150
SKDNSIRLSA GGDIWVTREP YVSCDPGKCY QFALGQGTTL DNKHSNDTIH
160 170 180 190 200
DRTPHRTLLM NELGVPFHLG TRQVCIAWSS SSCHDGKAWL HVCVTGYDKN
210 220 230 240 250
ATASFIYDGR LVDSIGSWSQ NILRTQESEC VCINGTCTVV MTDGSASGRA
260 270 280 290 300
DTKILFIEEG KIVHISPLSG SAQHVEECSC YPRYPGVRCI CRDNWKGSNR
310 320 330 340 350
PVVDINVKDY SIDSSYVCSG LVGDTPRNND RSSNSYCRNP NNEKGNHGVK
360 370 380 390 400
GWAFDDGNDV WMGRTISEDS RSGYETFKVI GGWSTPNSKL QINRQVIVDS
410 420 430 440 450
DNRSGYSGIF SVEGKSCINR CFYVELIRGR EQETRVWWTS NSIVVFCGTS
460
GTYGTGSWPD GADINLMPI
Length:469
Mass (Da):52,158
Last modified:May 16, 2006 - v1
Checksum:iA094092683621ACC
GO

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
CY009350 Genomic RNA. Translation: ABE12548.1.

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
CY009350 Genomic RNA. Translation: ABE12548.1.

3D structure databases

ProteinModelPortaliQ1PUD6.
ModBaseiSearch...
MobiDBiSearch...

Protein family/group databases

CAZyiGH34. Glycoside Hydrolase Family 34.

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Family and domain databases

CDDicd15483. Influenza_NA. 1 hit.
Gene3Di2.120.10.10. 1 hit.
InterProiIPR001860. Glyco_hydro_34.
IPR033654. Sialidase_Influenza_A/B.
IPR011040. Sialidases.
[Graphical view]
PfamiPF00064. Neur. 1 hit.
[Graphical view]
SUPFAMiSSF50939. SSF50939. 1 hit.
ProtoNetiSearch...

Entry informationi

Entry nameiNRAM_I73A5
AccessioniPrimary (citable) accession number: Q1PUD6
Entry historyi
Integrated into UniProtKB/Swiss-Prot: March 6, 2007
Last sequence update: May 16, 2006
Last modified: October 5, 2016
This is version 58 of the entry and version 1 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programViral Protein Annotation Program

Miscellaneousi

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.

Keywords - Technical termi

Complete proteome

Documents

  1. Glycosyl hydrolases
    Classification of glycosyl hydrolase families and list of entries
  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.