ID   3S13_MICSU              Reviewed;          60 AA.
AC   P86097;
DT   05-MAY-2009, integrated into UniProtKB/Swiss-Prot.
DT   05-MAY-2009, sequence version 1.
DT   25-MAY-2022, entry version 37.
DE   RecName: Full=Three-finger toxin MS3 {ECO:0000305};
DE   AltName: Full=Short neurotoxin MS3 {ECO:0000303|PubMed:18384102};
OS   Micrurus surinamensis (Surinam coral snake).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Elapidae; Elapinae; Micrurus.
OX   NCBI_TaxID=129470;
RN   [1]
RP   PROTEIN SEQUENCE, FUNCTION, AND SUBCELLULAR LOCATION.
RC   TISSUE=Venom;
RX   PubMed=18384102; DOI=10.1002/pmic.200700668;
RA   Olamendi-Portugal T., Batista C.V.F., Restano-Cassulini R., Pando V.,
RA   Villa-Hernandez O., Zavaleta-Martinez-Vargas A., Salas-Arruz M.C.,
RA   Rodriguez de la Vega R.C., Becerril B., Possani L.D.;
RT   "Proteomic analysis of the venom from the fish eating coral snake Micrurus
RT   surinamensis: novel toxins, their function and phylogeny.";
RL   Proteomics 8:1919-1932(2008).
CC   -!- FUNCTION: Produces peripheral paralysis by blocking neuromuscular
CC       transmission at the postsynaptic site. Binds to and inhibits the
CC       endogenous nicotinic acetylcholine receptors (nAChR) in human
CC       rhabdomyosarcoma TE 671 cell line with an IC(50) of 346 mM. This
CC       neurotoxin is lethal to mice by intraperitoneal injection and to
CC       zebrafish by injection at the back of the dorsolateral region.
CC       {ECO:0000269|PubMed:18384102}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:18384102}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305}.
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   AlphaFoldDB; P86097; -.
DR   SMR; P86097; -.
DR   GO; GO:0005576; C:extracellular region; IDA:UniProtKB.
DR   GO; GO:0030550; F:acetylcholine receptor inhibitor activity; IDA:UniProtKB.
DR   GO; GO:0099106; F:ion channel regulator activity; IEA:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin activity; IDA:UniProtKB.
DR   GO; GO:0044504; P:modulation of receptor activity in another organism; IDA:UniProtKB.
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; Toxin.
FT   CHAIN           1..60
FT                   /note="Three-finger toxin MS3"
FT                   /evidence="ECO:0000269|PubMed:18384102"
FT                   /id="PRO_0000371723"
FT   DISULFID        3..22
FT                   /evidence="ECO:0000250|UniProtKB:P60770"
FT   DISULFID        15..39
FT                   /evidence="ECO:0000250|UniProtKB:P60770"
FT   DISULFID        41..52
FT                   /evidence="ECO:0000250|UniProtKB:P60770"
FT   DISULFID        53..58
FT                   /evidence="ECO:0000250|UniProtKB:P60770"
SQ   SEQUENCE   60 AA;  6945 MW;  DE262522FDCB7AE4 CRC64;
     LICYSQMYNE IIKTCENGET TCYSKTWRDH RGTRLEKGCG CPPVKYDMIV KCCKTDRCGN