ID   3S12_AIPLA              Reviewed;          81 AA.
AC   P19959; P01439;
DT   01-FEB-1991, integrated into UniProtKB/Swiss-Prot.
DT   01-FEB-1991, sequence version 1.
DT   25-MAY-2022, entry version 92.
DE   RecName: Full=Short neurotoxin B;
DE   Flags: Precursor;
OS   Aipysurus laevis (Olive sea snake).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Hydrophiidae; Aipysurus.
OX   NCBI_TaxID=8678;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   TISSUE=Venom gland;
RX   PubMed=2330602; DOI=10.1016/0041-0101(90)90013-w;
RA   Ducancel F., Guignery-Frelat G., Boulain J.-C., Menez A.;
RT   "Nucleotide sequence and structure analysis of cDNAs encoding short-chain
RT   neurotoxins from venom glands of a sea snake (Aipysurus laevis).";
RL   Toxicon 28:119-123(1990).
RN   [2]
RP   PROTEIN SEQUENCE OF 22-81, AND SUBCELLULAR LOCATION.
RC   TISSUE=Venom;
RX   PubMed=1259717; DOI=10.1042/bj1530079;
RA   Maeda N., Tamiya N.;
RT   "Isolation, properties and amino acid sequences of three neurotoxins from
RT   the venom of a sea snake, Aipysurus laevis.";
RL   Biochem. J. 153:79-87(1976).
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:1259717}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305}.
CC   -!- TOXIC DOSE: LD(50) is 0.067 mg/kg by intramuscular injection into mice.
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; X13373; CAA31748.1; -; mRNA.
DR   PIR; A34019; A34019.
DR   AlphaFoldDB; P19959; -.
DR   SMR; P19959; -.
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..21
FT                   /evidence="ECO:0000269|PubMed:1259717"
FT   CHAIN           22..81
FT                   /note="Short neurotoxin B"
FT                   /evidence="ECO:0000269|PubMed:1259717"
FT                   /id="PRO_0000035433"
FT   DISULFID        24..43
FT                   /evidence="ECO:0000250|UniProtKB:P0C1Z0"
FT   DISULFID        38..60
FT                   /evidence="ECO:0000250|UniProtKB:P0C1Z0"
FT   DISULFID        62..73
FT                   /evidence="ECO:0000250|UniProtKB:P0C1Z0"
FT   DISULFID        74..79
FT                   /evidence="ECO:0000250|UniProtKB:P0C1Z0"
SQ   SEQUENCE   81 AA;  9048 MW;  E9D6403A5D59CE43 CRC64;
     MKTLLLTLVV VTIVCLDLGY TLTCCNQQSS QPKTTTDCAD NSCYKMTWRD HRGTRIERGC
     GCPQVKPGIK LECCKTNECN N