ID   3S12_HYDCY              Reviewed;          79 AA.
AC   P62376; A1EC57; P01436; P25493;
DT   21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT   15-JAN-2008, sequence version 2.
DT   25-MAY-2022, entry version 64.
DE   RecName: Full=Short neurotoxin 2;
DE   AltName: Full=Hydrophitoxin b;
DE   Flags: Precursor; Fragment;
OS   Hydrophis cyanocinctus (Asian annulated sea snake) (Leioselasma
OS   cyanocincta).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Hydrophiidae; Hydrophis.
OX   NCBI_TaxID=8686;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   TISSUE=Venom gland;
RA   Tan T., Bi Q., Xiang X., Zhu S.;
RT   "The study of the neurotoxins in sea snake using cDNA phage display
RT   technology.";
RL   Submitted (NOV-2006) to the EMBL/GenBank/DDBJ databases.
RN   [2]
RP   PROTEIN SEQUENCE OF 20-79, TOXIC DOSE, AND SUBCELLULAR LOCATION.
RC   TISSUE=Venom;
RX   PubMed=4460292; DOI=10.1016/0041-0101(74)90047-6;
RA   Lui C.-S., Blackwell R.Q.;
RT   "Hydrophitoxin b from Hydrophis cyanocinctus venom.";
RL   Toxicon 12:543-546(1974).
CC   -!- FUNCTION: Binds to muscle nicotinic acetylcholine receptor (nAChR) and
CC       inhibit acetylcholine from binding to the receptor, thereby impairing
CC       neuromuscular transmission. {ECO:0000250|UniProtKB:P60775}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:4460292}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305}.
CC   -!- TOXIC DOSE: LD(50) is 0.085 mg/kg by intravenous injection.
CC       {ECO:0000269|PubMed:4460292}.
CC   -!- SIMILARITY: Belongs to the snake three-finger toxin family. Short-chain
CC       subfamily. Type I alpha-neurotoxin sub-subfamily. {ECO:0000305}.
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DR   EMBL; EF121774; ABL61579.1; -; mRNA.
DR   AlphaFoldDB; P62376; -.
DR   SMR; P62376; -.
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   InterPro; IPR018354; Snake_toxin_con_site.
DR   SUPFAM; SSF57302; SSF57302; 1.
DR   PROSITE; PS00272; SNAKE_TOXIN; 1.
PE   1: Evidence at protein level;
KW   Acetylcholine receptor inhibiting toxin; Direct protein sequencing;
KW   Disulfide bond; Ion channel impairing toxin; Neurotoxin;
KW   Postsynaptic neurotoxin; Secreted; Signal; Toxin.
FT   SIGNAL          <1..19
FT                   /evidence="ECO:0000269|PubMed:4460292"
FT   CHAIN           20..79
FT                   /note="Short neurotoxin 2"
FT                   /evidence="ECO:0000269|PubMed:4460292"
FT                   /id="PRO_0000093578"
FT   DISULFID        22..41
FT                   /evidence="ECO:0000250|UniProtKB:P0C1Z0"
FT   DISULFID        36..58
FT                   /evidence="ECO:0000250|UniProtKB:P0C1Z0"
FT   DISULFID        60..71
FT                   /evidence="ECO:0000250|UniProtKB:P0C1Z0"
FT   DISULFID        72..77
FT                   /evidence="ECO:0000250|UniProtKB:P0C1Z0"
FT   NON_TER         1
SQ   SEQUENCE   79 AA;  8715 MW;  0084A281CEBFF996 CRC64;
     PLLLTLVVVT IVCLDLGYTM TCCNQQSSQP KTTTNCAESS CYKKTWSDHR GTRIERGCGC
     PQVKSGIKLE CCHTNECNN