K7PQX9 · K7PQX9_9INFA
- ProteinNeuraminidase
- GeneNA
- StatusUniProtKB unreviewed (TrEMBL)
- Amino acids469 (go to sequence)
- Protein existenceInferred from homology
- Annotation score4/5
Function
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
Cofactor
Activity 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.
Features
Showing features for binding site, active site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Binding site | 118 | substrate | ||||
Sequence: R | ||||||
Active site | 151 | Proton donor/acceptor | ||||
Sequence: D | ||||||
Binding site | 152 | substrate | ||||
Sequence: R | ||||||
Binding site | 277-278 | substrate | ||||
Sequence: EE | ||||||
Binding site | 293 | substrate | ||||
Sequence: R | ||||||
Binding site | 294 | Ca2+ (UniProtKB | ChEBI) | ||||
Sequence: D | ||||||
Binding site | 298 | Ca2+ (UniProtKB | ChEBI) | ||||
Sequence: G | ||||||
Binding site | 324 | Ca2+ (UniProtKB | ChEBI) | ||||
Sequence: D | ||||||
Binding site | 344 | Ca2+ (UniProtKB | ChEBI) | ||||
Sequence: N | ||||||
Binding site | 368 | substrate | ||||
Sequence: R | ||||||
Active site | 402 | Nucleophile | ||||
Sequence: Y |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | host cell plasma membrane | |
Cellular Component | membrane | |
Cellular Component | virion membrane | |
Molecular Function | exo-alpha-(2->3)-sialidase activity | |
Molecular Function | exo-alpha-(2->6)-sialidase activity | |
Molecular Function | exo-alpha-(2->8)-sialidase activity | |
Molecular Function | metal ion binding | |
Biological Process | carbohydrate metabolic process | |
Biological Process | viral budding from plasma membrane |
Keywords
- Molecular function
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameNeuraminidase
- EC number
Gene names
Organism names
- Strain
- Taxonomic lineageViruses > Riboviria > Orthornavirae > Negarnaviricota > Polyploviricotina > Insthoviricetes > Articulavirales > Orthomyxoviridae > Alphainfluenzavirus > Alphainfluenzavirus influenzae > Influenza A virus
Accessions
- Primary accessionK7PQX9
Proteomes
Subcellular Location
UniProt Annotation
GO Annotation
Membrane ; Single-pass type II membrane protein
Host apical cell membrane ; Single-pass type II membrane protein
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.
Features
Showing features for transmembrane.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Transmembrane | 7-34 | Helical | ||||
Sequence: IIIISSICMTNGIASLILQIGSMISIWI |
Keywords
- Cellular component
PTM/Processing
Features
Showing features for disulfide bond.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Disulfide bond | 92↔417 | |||||
Sequence: CPVSGWAIYSKDNSVRIGSKGDVFVIREPFISCSHLECRTFFLTQGALLNDKHSNGTVKDRSPYRTLMSCPIGEVPSPYNSKFESVAWSASACHDGTSWLTIGISGPDNGAVAVLKYNDIITDTIKSWKNNILRTQESECACLNGSCFTVMTDGPSNGQASYKIFKIEKGKVVKSVELNAPNYHYEECSCYPDSGEIICVCRDNWHGSNRPWVSFNQNLEYQIGYICSGVLGDNPRPNDRTGSCGPVSSHGANGVKGFSFKYGNGIWIGRTKSISSRSGFEMIWDPNGWTGTDNNYSVKQDIVGITDWSGYSGSFVQHPELTGLDC | ||||||
Disulfide bond | 124↔129 | |||||
Sequence: CSHLEC | ||||||
Disulfide bond | 184↔231 | |||||
Sequence: CHDGTSWLTIGISGPDNGAVAVLKYNDIITDTIKSWKNNILRTQESEC | ||||||
Disulfide bond | 233↔238 | |||||
Sequence: CLNGSC | ||||||
Disulfide bond | 279↔292 | |||||
Sequence: CSCYPDSGEIICVC | ||||||
Disulfide bond | 281↔290 | |||||
Sequence: CYPDSGEIIC | ||||||
Disulfide bond | 318↔335 | |||||
Sequence: CSGVLGDNPRPNDRTGSC | ||||||
Disulfide bond | 421↔446 | |||||
Sequence: CFWVELIRGRPKENTIWTSGSSISFC |
Post-translational modification
N-glycosylated.
Keywords
- PTM
Interaction
Subunit
Homotetramer.
Structure
Family & Domains
Features
Showing features for region.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Region | 11-33 | Involved in apical transport and lipid raft association | ||||
Sequence: SSICMTNGIASLILQIGSMISIW | ||||||
Region | 91-469 | Head of neuraminidase | ||||
Sequence: LCPVSGWAIYSKDNSVRIGSKGDVFVIREPFISCSHLECRTFFLTQGALLNDKHSNGTVKDRSPYRTLMSCPIGEVPSPYNSKFESVAWSASACHDGTSWLTIGISGPDNGAVAVLKYNDIITDTIKSWKNNILRTQESECACLNGSCFTVMTDGPSNGQASYKIFKIEKGKVVKSVELNAPNYHYEECSCYPDSGEIICVCRDNWHGSNRPWVSFNQNLEYQIGYICSGVLGDNPRPNDRTGSCGPVSSHGANGVKGFSFKYGNGIWIGRTKSISSRSGFEMIWDPNGWTGTDNNYSVKQDIVGITDWSGYSGSFVQHPELTGLDCIRPCFWVELIRGRPKENTIWTSGSSISFCGVNSDTVGWSWPDGAELPFIIDK |
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.
Sequence similarities
Belongs to the glycosyl hydrolase 34 family.
Keywords
- Domain
Family and domain databases
Sequence
- Sequence statusComplete
- Length469
- Mass (Da)51,628
- Last updated2013-02-06 v1
- Checksum86E2F63175D04F3A