ID   3S33_PSETE              Reviewed;          79 AA.
AC   Q9W7K0;
DT   01-NOV-2002, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1999, sequence version 1.
DT   25-MAY-2022, entry version 81.
DE   RecName: Full=Short neurotoxin 3;
DE            Short=SNTX3;
DE   AltName: Full=Alpha-neurotoxin 3;
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], FUNCTION, AND TOXIC 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].
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).
RN   [3]
RP   IDENTIFICATION BY MASS SPECTROMETRY, AND SUBCELLULAR LOCATION.
RC   TISSUE=Venom;
RX   PubMed=16284125; DOI=10.1074/mcp.m500270-mcp200;
RA   Birrell G.W., Earl S., Masci P.P., de Jersey J., Wallis T.P., Gorman J.J.,
RA   Lavin M.F.;
RT   "Molecular diversity in venom from the Australian Brown snake, Pseudonaja
RT   textilis.";
RL   Mol. Cell. Proteomics 5:379-389(2006).
CC   -!- FUNCTION: Binds with high affinity to muscle nicotinic acetylcholine
CC       receptor (nAChR) and hinders acetylcholine binding to the receptor,
CC       thereby impairing neuromuscular transmission. Competes with the binding
CC       of alpha-bungarotoxin on muscle AChR (from Torpedo) with an IC(50) of
CC       0.30 uM. Causes muscle paralysis, spasms and increased respiration.
CC       {ECO:0000269|PubMed:10518793}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:16284125}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000305|PubMed:16284125}.
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; AF082977; AAD40969.1; -; mRNA.
DR   EMBL; AF204971; AAF75222.1; -; Genomic_DNA.
DR   AlphaFoldDB; Q9W7K0; -.
DR   SMR; Q9W7K0; -.
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   1: Evidence at protein level;
KW   Acetylcholine receptor inhibiting toxin; Disulfide bond;
KW   Ion channel impairing toxin; Neurotoxin; Postsynaptic neurotoxin;
KW   Reference proteome; Secreted; Signal; Toxin.
FT   SIGNAL          1..21
FT                   /evidence="ECO:0000250"
FT   CHAIN           22..79
FT                   /note="Short neurotoxin 3"
FT                   /id="PRO_0000035463"
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"
SQ   SEQUENCE   79 AA;  8582 MW;  2FB20C63A75215BD CRC64;
     MKTLLLTLVM VTIMCLDLGY TLTCYKGYHD TVVCKPHETI CYRYLVPATH GNAIPARGCG
     TSCPGGNHPV CCSTDLCNK