ID   NRAM_I82A2              Reviewed;         103 AA.
AC   P26143;
DT   01-MAY-1992, integrated into UniProtKB/Swiss-Prot.
DT   01-MAY-1992, sequence version 1.
DT   08-NOV-2023, entry version 113.
DE   RecName: Full=Neuraminidase;
DE            EC=3.2.1.18;
DE   Flags: Fragment;
GN   Name=NA;
OS   Influenza A virus (strain A/Camel/Mongolia/1982 H1N1).
OC   Viruses; Riboviria; Orthornavirae; Negarnaviricota; Polyploviricotina;
OC   Insthoviricetes; Articulavirales; Orthomyxoviridae; Alphainfluenzavirus;
OC   Alphainfluenzavirus influenzae; Influenza A virus.
OX   NCBI_TaxID=387191;
OH   NCBI_TaxID=8782; Aves.
OH   NCBI_TaxID=9606; Homo sapiens (Human).
OH   NCBI_TaxID=9823; Sus scrofa (Pig).
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RX   PubMed=8249279; DOI=10.1006/viro.1993.1629;
RA   Yamnikova S.S., Mandler J., Bekh-Ochir Z.H., Dachtzeren P., Ludwig S.,
RA   Lvov D.K., Scholtissek C.;
RT   "A reassortant H1N1 influenza A virus caused fatal epizootics among camels
RT   in Mongolia.";
RL   Virology 197:558-563(1993).
RN   [2]
RP   REVIEW.
RX   PubMed=15567494; DOI=10.1016/j.virusres.2004.08.012;
RA   Nayak D.P., Hui E.K., Barman S.;
RT   "Assembly and budding of influenza virus.";
RL   Virus Res. 106:147-165(2004).
RN   [3]
RP   REVIEW.
RX   PubMed=16192481; DOI=10.1056/nejmra050740;
RA   Moscona A.;
RT   "Neuraminidase inhibitors for influenza.";
RL   N. Engl. J. Med. 353:1363-1373(2005).
RN   [4]
RP   REVIEW.
RX   PubMed=15744059; DOI=10.1248/bpb.28.399;
RA   Suzuki Y.;
RT   "Sialobiology of influenza: molecular mechanism of host range variation of
RT   influenza viruses.";
RL   Biol. Pharm. Bull. 28:399-408(2005).
CC   -!- FUNCTION: Catalyzes the removal of terminal sialic acid residues from
CC       viral and cellular glycoconjugates. Cleaves off the terminal sialic
CC       acids on the glycosylated HA during virus budding to facilitate virus
CC       release. Additionally helps virus spread through the circulation by
CC       further removing sialic acids from the cell surface. These cleavages
CC       prevent self-aggregation and ensure the efficient spread of the progeny
CC       virus from cell to cell. Otherwise, infection would be limited to one
CC       round of replication. Described as a receptor-destroying enzyme because
CC       it cleaves a terminal sialic acid from the cellular receptors. May
CC       facilitate viral invasion of the upper airways by cleaving the sialic
CC       acid moieties on the mucin of the airway epithelial cells. Likely to
CC       plays a role in the budding process through its association with lipid
CC       rafts during intracellular transport. May additionally display a raft-
CC       association independent effect on budding. Plays a role in the
CC       determination of host range restriction on replication and virulence.
CC       Sialidase activity in late endosome/lysosome traffic seems to enhance
CC       virus replication.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Hydrolysis of alpha-(2->3)-, alpha-(2->6)-, alpha-
CC         (2->8)- glycosidic linkages of terminal sialic acid residues in
CC         oligosaccharides, glycoproteins, glycolipids, colominic acid and
CC         synthetic substrates.; EC=3.2.1.18;
CC   -!- COFACTOR:
CC       Name=Ca(2+); Xref=ChEBI:CHEBI:29108; Evidence={ECO:0000250};
CC       Note=Binds 1 Ca(2+) ion per subunit. {ECO:0000250};
CC   -!- ACTIVITY REGULATION: Inhibited by the neuraminidase inhibitors
CC       zanamivir (Relenza) and oseltamivir (Tamiflu). These drugs interfere
CC       with the release of progeny virus from infected cells and are effective
CC       against all influenza strains. Resistance to neuraminidase inhibitors
CC       is quite rare.
CC   -!- SUBUNIT: Homotetramer. {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Virion membrane {ECO:0000250}. Host apical cell
CC       membrane {ECO:0000250}; Single-pass type II membrane protein
CC       {ECO:0000250}. Note=Preferentially accumulates at the apical plasma
CC       membrane in infected polarized epithelial cells, which is the virus
CC       assembly site. Uses lipid rafts for cell surface transport and apical
CC       sorting. In the virion, forms a mushroom-shaped spike on the surface of
CC       the membrane (By similarity). {ECO:0000250}.
CC   -!- DOMAIN: Intact N-terminus is essential for virion morphogenesis.
CC       Possesses two apical sorting signals, one in the ectodomain, which is
CC       likely to be a glycan, and the other in the transmembrane domain. The
CC       transmembrane domain also plays a role in lipid raft association (By
CC       similarity). {ECO:0000250}.
CC   -!- PTM: N-glycosylated. {ECO:0000250}.
CC   -!- MISCELLANEOUS: The influenza A genome consist of 8 RNA segments.
CC       Genetic variation of hemagglutinin and/or neuraminidase genes results
CC       in the emergence of new influenza strains. The mechanism of variation
CC       can be the result of point mutations or the result of genetic
CC       reassortment between segments of two different strains.
CC   -!- SIMILARITY: Belongs to the glycosyl hydrolase 34 family. {ECO:0000305}.
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DR   EMBL; M73976; AAA16907.1; -; mRNA.
DR   CAZy; GH34; Glycoside Hydrolase Family 34.
DR   GlyCosmos; P26143; 5 sites, No reported glycans.
DR   GO; GO:0020002; C:host cell plasma membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0016020; C:membrane; IEA:UniProtKB-KW.
DR   GO; GO:0055036; C:virion membrane; IEA:UniProtKB-SubCell.
DR   GO; GO:0052794; F:exo-alpha-(2->3)-sialidase activity; IEA:UniProtKB-EC.
DR   GO; GO:0052795; F:exo-alpha-(2->6)-sialidase activity; IEA:UniProtKB-EC.
DR   GO; GO:0052796; F:exo-alpha-(2->8)-sialidase activity; IEA:UniProtKB-EC.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0008152; P:metabolic process; IEA:UniProtKB-KW.
DR   Gene3D; 2.120.10.10; -; 1.
DR   InterPro; IPR036278; Sialidase_sf.
DR   SUPFAM; SSF50939; Sialidases; 1.
PE   2: Evidence at transcript level;
KW   Calcium; Glycoprotein; Glycosidase; Host cell membrane; Host membrane;
KW   Hydrolase; Membrane; Metal-binding; Signal-anchor; Transmembrane;
KW   Transmembrane helix; Virion.
FT   CHAIN           <1..>103
FT                   /note="Neuraminidase"
FT                   /id="PRO_0000078678"
FT   TRANSMEM        <1..18
FT                   /note="Helical; Signal-anchor for type II membrane protein"
FT                   /evidence="ECO:0000255"
FT   TOPO_DOM        19..>103
FT                   /note="Virion surface"
FT                   /evidence="ECO:0000255"
FT   BINDING         101
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250"
FT   CARBOHYD        27
FT                   /note="N-linked (GlcNAc...) asparagine; by host"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        41
FT                   /note="N-linked (GlcNAc...) asparagine; by host"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        46
FT                   /note="N-linked (GlcNAc...) asparagine; by host"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        51
FT                   /note="N-linked (GlcNAc...) asparagine; by host"
FT                   /evidence="ECO:0000255"
FT   CARBOHYD        71
FT                   /note="N-linked (GlcNAc...) asparagine; by host"
FT                   /evidence="ECO:0000255"
FT   NON_TER         1
FT   NON_TER         103
SQ   SEQUENCE   103 AA;  11253 MW;  F8474BC2B3D3B310 CRC64;
     GIISLILQIG NIISIWVSHS IQTGSQNHTG ICNQRIITYE NSTWVNQTYV NISNTNVVAG
     KDTTSMTLAG NSSLCPIRGW AIYSKDNSIR IGSKGDVFVI REP
//