ID   3S31_PSETE              Reviewed;          79 AA.
AC   Q9W7K2; Q9W7J8;
DT   01-NOV-2002, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1999, sequence version 1.
DT   25-MAY-2022, entry version 79.
DE   RecName: Full=Short neurotoxin 1/5;
DE            Short=SNTX1;
DE            Short=SNTX5;
DE   AltName: Full=Alpha-neurotoxin 1/5;
DE   Flags: Precursor;
OS   Pseudonaja textilis (Eastern brown snake).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Elapidae; Acanthophiinae; Pseudonaja.
OX   NCBI_TaxID=8673;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA] (ISOFORMS SNTX1 AND SNTX5), FUNCTION, AND TOXIC
RP   DOSE.
RC   TISSUE=Venom gland;
RX   PubMed=10518793; DOI=10.1046/j.1432-1327.1999.00800.x;
RA   Gong N.L., Armugam A., Jeyaseelan K.;
RT   "Postsynaptic short-chain neurotoxins from Pseudonaja textilis: cDNA
RT   cloning, expression and protein characterization.";
RL   Eur. J. Biochem. 265:982-989(1999).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA] (ISOFORMS SNTX1 AND SNTX5).
RC   TISSUE=Liver;
RX   PubMed=10818230; DOI=10.1016/s0014-5793(00)01549-0;
RA   Gong N.L., Armugam A., Jeyaseelan K.;
RT   "Molecular cloning, characterization and evolution of the genes encoding a
RT   new group of short-chain alpha-neurotoxins in an Australian elapid,
RT   Pseudonaja textilis.";
RL   FEBS Lett. 473:303-310(2000).
CC   -!- FUNCTION: Binds with high affinity to muscle nicotinic acetylcholine
CC       receptor (nAChR) and inhibit acetylcholine from binding to the
CC       receptor, thereby impairing neuromuscular transmission. Compete with
CC       the binding of alpha-bungarotoxin on muscle AChR (from Torpedo) with an
CC       IC(50) of 0.31 uM (SNTX1) and 3.1 uM (SNTX5). Is able of exerting
CC       muscle paralysis, spasms and increased respiration.
CC       {ECO:0000269|PubMed:10518793}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000250}.
CC   -!- ALTERNATIVE PRODUCTS:
CC       Event=Alternative splicing; Named isoforms=2;
CC       Name=SNTX1;
CC         IsoId=Q9W7K2-1; Sequence=Displayed;
CC       Name=SNTX5;
CC         IsoId=Q9W7K2-2; Sequence=VSP_006534;
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305}.
CC   -!- TOXIC DOSE: LD(50) is 1 mg/kg by intravenous injection into mice.
CC       {ECO:0000269|PubMed:10518793}.
CC   -!- SIMILARITY: Belongs to the snake three-finger toxin family. Short-chain
CC       subfamily. Type III alpha-neurotoxin sub-subfamily. {ECO:0000305}.
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DR   EMBL; AF082975; AAD40967.1; -; mRNA.
DR   EMBL; AF082979; AAD40971.1; -; mRNA.
DR   EMBL; AF204969; AAF75220.1; -; Genomic_DNA.
DR   AlphaFoldDB; Q9W7K2; -.
DR   SMR; Q9W7K2; -.
DR   Proteomes; UP000472273; Unplaced.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0030550; F:acetylcholine receptor inhibitor activity; IEA:UniProtKB-KW.
DR   GO; GO:0099106; F:ion channel regulator activity; IEA:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   CDD; cd00206; snake_toxin; 1.
DR   Gene3D; 2.10.60.10; -; 1.
DR   InterPro; IPR003571; Snake_3FTx.
DR   InterPro; IPR045860; Snake_toxin-like_sf.
DR   SUPFAM; SSF57302; SSF57302; 1.
PE   3: Inferred from homology;
KW   Acetylcholine receptor inhibiting toxin; Alternative splicing;
KW   Disulfide bond; Ion channel impairing toxin; Neurotoxin;
KW   Postsynaptic neurotoxin; Reference proteome; Secreted; Signal; Toxin.
FT   SIGNAL          1..21
FT                   /evidence="ECO:0000250"
FT   CHAIN           22..79
FT                   /note="Short neurotoxin 1/5"
FT                   /id="PRO_0000035461"
FT   DISULFID        24..41
FT                   /evidence="ECO:0000250|UniProtKB:P60301"
FT   DISULFID        34..59
FT                   /evidence="ECO:0000250|UniProtKB:P60301"
FT   DISULFID        63..71
FT                   /evidence="ECO:0000250|UniProtKB:P60301"
FT   DISULFID        72..77
FT                   /evidence="ECO:0000250|UniProtKB:P60301"
FT   VAR_SEQ         51..52
FT                   /note="GN -> D (in isoform SNTX5)"
FT                   /evidence="ECO:0000303|PubMed:10518793"
FT                   /id="VSP_006534"
FT   CONFLICT        73
FT                   /note="R -> T (in Ref. 1; AAD40971)"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   79 AA;  8706 MW;  3260664A3D89FA1D CRC64;
     MKTLLLTLVM VTIMCLDLGY TLTCYKGYHD TVVCKPHETI CYEYFIPATH GNAILARGCG
     TSCPGGIRPV CCRTDLCNK