ID   SCX3_CENEX              Reviewed;          69 AA.
AC   Q68PH2;
DT   31-OCT-2006, integrated into UniProtKB/Swiss-Prot.
DT   11-OCT-2004, sequence version 1.
DT   03-AUG-2022, entry version 51.
DE   RecName: Full=Neurotoxin Cex3;
DE   Flags: Precursor; Fragment;
OS   Centruroides exilicauda (Bark scorpion) (Buthus exilicauda).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Centruroides.
OX   NCBI_TaxID=6879;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   TISSUE=Venom gland;
RX   PubMed=15358055; DOI=10.1016/j.biochi.2004.05.005;
RA   Valdez-Cruz N.A., Davila S., Licea A., Corona M., Zamudio F.Z.,
RA   Garcia-Valdes J., Boyer L., Possani L.D.;
RT   "Biochemical, genetic and physiological characterization of venom
RT   components from two species of scorpions: Centruroides exilicauda Wood and
RT   Centruroides sculpturatus Ewing.";
RL   Biochimie 86:387-396(2004).
CC   -!- FUNCTION: Beta toxins bind voltage-independently at site-4 of sodium
CC       channels (Nav) and shift the voltage of activation toward more negative
CC       potentials thereby affecting sodium channel activation and promoting
CC       spontaneous and repetitive firing. {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000250}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC   -!- DOMAIN: Has the structural arrangement of an alpha-helix connected to
CC       antiparallel beta-sheets by disulfide bonds (CS-alpha/beta).
CC       {ECO:0000305}.
CC   -!- SIMILARITY: Belongs to the long (4 C-C) scorpion toxin superfamily.
CC       Sodium channel inhibitor family. Beta subfamily. {ECO:0000305}.
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DR   EMBL; AY649861; AAT97994.1; -; mRNA.
DR   AlphaFoldDB; Q68PH2; -.
DR   SMR; Q68PH2; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0019871; F:sodium channel inhibitor activity; IEA:InterPro.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   GO; GO:0006952; P:defense response; IEA:InterPro.
DR   Gene3D; 3.30.30.10; -; 1.
DR   InterPro; IPR044062; LCN-type_CS_alpha_beta_dom.
DR   InterPro; IPR003614; Scorpion_toxin-like.
DR   InterPro; IPR036574; Scorpion_toxin-like_sf.
DR   InterPro; IPR018218; Scorpion_toxinL.
DR   InterPro; IPR002061; Scorpion_toxinL/defensin.
DR   Pfam; PF00537; Toxin_3; 1.
DR   PRINTS; PR00285; SCORPNTOXIN.
DR   SMART; SM00505; Knot1; 1.
DR   SUPFAM; SSF57095; SSF57095; 1.
DR   PROSITE; PS51863; LCN_CSAB; 1.
PE   2: Evidence at transcript level;
KW   Amidation; Disulfide bond; Ion channel impairing toxin; Neurotoxin;
KW   Secreted; Signal; Toxin; Voltage-gated sodium channel impairing toxin.
FT   SIGNAL          <1..1
FT                   /evidence="ECO:0000255"
FT   CHAIN           2..66
FT                   /note="Neurotoxin Cex3"
FT                   /id="PRO_0000254066"
FT   PROPEP          67..69
FT                   /id="PRO_0000254067"
FT   DOMAIN          2..67
FT                   /note="LCN-type CS-alpha/beta"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   MOD_RES         66
FT                   /note="Cysteine amide"
FT                   /evidence="ECO:0000255"
FT   DISULFID        13..66
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        17..42
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        26..47
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        30..49
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   NON_TER         1
SQ   SEQUENCE   69 AA;  7745 MW;  0233380932AD3236 CRC64;
     AKDGYLVNKS TGCKYECFWL GKNEFCDKEC KAKNQGGSYG YCYSFACWCE GLPESTSTYP
     LPNKSCGRK