ID   3S11_HYDHA              Reviewed;          81 AA.
AC   P68416; A3FM51; A3FM52; P01436; P25492;
DT   21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT   15-JAN-2008, sequence version 2.
DT   25-MAY-2022, entry version 63.
DE   RecName: Full=Short neurotoxin 1;
DE   AltName: Full=SN12;
DE   AltName: Full=Toxin 4;
DE   Flags: Precursor;
OS   Hydrophis hardwickii (Hardwick's spine-bellied seasnake) (Lapemis
OS   hardwickii).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Hydrophiidae; Hydrophis.
OX   NCBI_TaxID=8781;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], AND TOXIC DOSE.
RC   TISSUE=Venom gland;
RX   PubMed=12040423;
RA   Zhong X.F., Peng L.S., Wu W.Y., Wei J.W., Yang H., Yang Y.Z., Xu A.L.;
RT   "Identification and functional characterization of three postsynaptic
RT   short-chain neurotoxins from hydrophiinae, Lapemis hardwickii Gray.";
RL   Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao 33:457-462(2001).
RN   [2]
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 (JAN-2007) to the EMBL/GenBank/DDBJ databases.
RN   [3]
RP   PROTEIN SEQUENCE OF 22-81, AND SUBCELLULAR LOCATION.
RC   TISSUE=Venom;
RX   PubMed=891966; DOI=10.1016/0014-5793(77)80443-2;
RA   Fox J.W., Elzinga M., Tu A.T.;
RT   "Amino acid sequence of a snake neurotoxin from the venom of Lapemis
RT   hardwickii and the detection of a sulfhydryl group by laser Raman
RT   spectroscopy.";
RL   FEBS Lett. 80:217-220(1977).
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:891966}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305}.
CC   -!- TOXIC DOSE: LD(50) is 0.0956 mg/kg by intraperitoneal injection into
CC       mice. {ECO:0000269|PubMed:12040423}.
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; EF405869; ABN54804.1; -; mRNA.
DR   EMBL; EF405870; ABN54805.1; -; mRNA.
DR   AlphaFoldDB; P68416; -.
DR   SMR; P68416; -.
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:891966"
FT   CHAIN           22..81
FT                   /note="Short neurotoxin 1"
FT                   /evidence="ECO:0000269|PubMed:891966"
FT                   /id="PRO_0000093585"
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"
FT   CONFLICT        3
FT                   /note="T -> L (in Ref. 2; ABN54805)"
FT                   /evidence="ECO:0000305"
FT   CONFLICT        63
FT                   /note="P -> S (in Ref. 2; ABN54805)"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   81 AA;  8988 MW;  F3F62372BB2ECF10 CRC64;
     MKTLLLTLVV VTIVCLDLGY TMTCCNQQSS QPKTTTNCAE SSCYKKTWSD HRGTRIERGC
     GCPQVKPGIK LECCHTNECN N