ID   3NX4_MICSU              Reviewed;          64 AA.
AC   P86098;
DT   05-MAY-2009, integrated into UniProtKB/Swiss-Prot.
DT   05-MAY-2009, sequence version 1.
DT   25-MAY-2022, entry version 35.
DE   RecName: Full=Long neurotoxin MS4 {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. Weak inhibitor of the endogenous
CC       nicotinic acetylcholine receptors (nAChR) in the human rhabdomyosarcoma
CC       TE 671 cell line with an IC(50) of 690 mM. This neurotoxin is lethal to
CC       zebrafish by injection at the back of the dorsolateral region, but is
CC       not toxic to mice by intraperitoneal injection.
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. Ancestral
CC       subfamily. {ECO:0000305}.
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DR   AlphaFoldDB; P86098; -.
DR   SMR; P86098; -.
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   SUPFAM; SSF57302; SSF57302; 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..64
FT                   /note="Long neurotoxin MS4"
FT                   /evidence="ECO:0000269|PubMed:18384102"
FT                   /id="PRO_0000371720"
FT   DISULFID        3..24
FT                   /evidence="ECO:0000250|UniProtKB:P81783"
FT   DISULFID        6..11
FT                   /evidence="ECO:0000250|UniProtKB:P81783"
FT   DISULFID        17..41
FT                   /evidence="ECO:0000250|UniProtKB:P81783"
FT   DISULFID        45..57
FT                   /evidence="ECO:0000250|UniProtKB:P81783"
FT   DISULFID        58..63
FT                   /evidence="ECO:0000250|UniProtKB:P81783"
SQ   SEQUENCE   64 AA;  7312 MW;  59093512E9345EF1 CRC64;
     LTCKTCPFNT CANSETCPAG KNICYQKKWE EHRGERIERR CVANCPKLGS NDKSLLCCRR
     DDCN