ID   SCX12_CENNO             Reviewed;          67 AA.
AC   P63019;
DT   31-AUG-2004, integrated into UniProtKB/Swiss-Prot.
DT   31-AUG-2004, sequence version 1.
DT   03-AUG-2022, entry version 72.
DE   RecName: Full=Alpha-toxin Cn12 {ECO:0000303|PubMed:15182366};
OS   Centruroides noxius (Mexican scorpion).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Centruroides.
OX   NCBI_TaxID=6878;
RN   [1]
RP   PROTEIN SEQUENCE, FUNCTION, MASS SPECTROMETRY, STRUCTURE BY NMR, DISULFIDE
RP   BONDS, AND SUBCELLULAR LOCATION.
RC   TISSUE=Venom;
RX   PubMed=15182366; DOI=10.1111/j.1432-1033.2004.04181.x;
RA   del Rio-Portilla F., Hernandez-Marin E., Pimienta G., Coronas F.V.,
RA   Zamudio F.Z., Rodriguez de la Vega R.C., Wanke E., Possani L.D.;
RT   "NMR solution structure of Cn12, a novel peptide from the Mexican scorpion
RT   Centruroides noxius with a typical beta-toxin sequence but with alpha-like
RT   physiological activity.";
RL   Eur. J. Biochem. 271:2504-2516(2004).
CC   -!- FUNCTION: Alpha toxins bind voltage-independently at site-3 of sodium
CC       channels (Nav) and inhibit the inactivation of the activated channels,
CC       thereby blocking neuronal transmission. This toxin binds, in vitro, to
CC       sodium channels and inhibits the inactivation of the activated
CC       channels. Seems not toxic to mice, crickets and sweet-water shrimps.
CC       {ECO:0000269|PubMed:15182366}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:15182366}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000305|PubMed:15182366}.
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   -!- MASS SPECTROMETRY: Mass=7139.5; Method=Unknown;
CC       Evidence={ECO:0000269|PubMed:15182366};
CC   -!- SIMILARITY: Belongs to the long (4 C-C) scorpion toxin superfamily.
CC       Sodium channel inhibitor family. Beta subfamily. {ECO:0000305}.
CC   -!- CAUTION: This toxin sequence resembles the beta scorpion toxin class,
CC       although patch-clamp experiments shows the induction of supplementary
CC       slow inactivation of sodium channels, which means that it behaves like
CC       an alpha scorpion toxin. {ECO:0000305}.
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DR   PDB; 1PE4; NMR; -; A=1-67.
DR   PDBsum; 1PE4; -.
DR   AlphaFoldDB; P63019; -.
DR   BMRB; P63019; -.
DR   SMR; P63019; -.
DR   TCDB; 8.B.1.1.13; the long (4c-c) scorpion toxin (l-st) superfamily.
DR   EvolutionaryTrace; P63019; -.
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   Gene3D; 3.30.30.10; -; 1.
DR   InterPro; IPR044062; LCN-type_CS_alpha_beta_dom.
DR   InterPro; IPR036574; Scorpion_toxin-like_sf.
DR   InterPro; IPR002061; Scorpion_toxinL/defensin.
DR   Pfam; PF00537; Toxin_3; 1.
DR   SUPFAM; SSF57095; SSF57095; 1.
DR   PROSITE; PS51863; LCN_CSAB; 1.
PE   1: Evidence at protein level;
KW   3D-structure; Direct protein sequencing; Disulfide bond;
KW   Ion channel impairing toxin; Neurotoxin; Secreted; Toxin;
KW   Voltage-gated sodium channel impairing toxin.
FT   CHAIN           1..67
FT                   /note="Alpha-toxin Cn12"
FT                   /evidence="ECO:0000269|PubMed:15182366"
FT                   /id="PRO_0000066772"
FT   DOMAIN          1..66
FT                   /note="LCN-type CS-alpha/beta"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        11..65
FT                   /evidence="ECO:0000269|PubMed:15182366,
FT                   ECO:0007744|PDB:1PE4"
FT   DISULFID        15..40
FT                   /evidence="ECO:0000269|PubMed:15182366,
FT                   ECO:0007744|PDB:1PE4"
FT   DISULFID        25..45
FT                   /evidence="ECO:0000269|PubMed:15182366,
FT                   ECO:0007744|PDB:1PE4"
FT   DISULFID        29..47
FT                   /evidence="ECO:0000269|PubMed:15182366,
FT                   ECO:0007744|PDB:1PE4"
FT   STRAND          8..10
FT                   /evidence="ECO:0007829|PDB:1PE4"
FT   STRAND          12..14
FT                   /evidence="ECO:0007829|PDB:1PE4"
FT   HELIX           25..31
FT                   /evidence="ECO:0007829|PDB:1PE4"
FT   STRAND          41..44
FT                   /evidence="ECO:0007829|PDB:1PE4"
FT   STRAND          46..49
FT                   /evidence="ECO:0007829|PDB:1PE4"
FT   STRAND          51..53
FT                   /evidence="ECO:0007829|PDB:1PE4"
FT   STRAND          63..65
FT                   /evidence="ECO:0007829|PDB:1PE4"
SQ   SEQUENCE   67 AA;  7148 MW;  B7BCAE8566FEC0EC CRC64;
     RDGYPLASNG CKFGCSGLGE NNPTCNHVCE KKAGSDYGYC YAWTCYCEHV AEGTVLWGDS
     GTGPCRS