ID   SCX7_CENNO              Reviewed;          55 AA.
AC   Q9TWL1;
DT   16-JAN-2004, integrated into UniProtKB/Swiss-Prot.
DT   01-MAY-2000, sequence version 1.
DT   03-AUG-2022, entry version 70.
DE   RecName: Full=Beta-toxin Cn7;
DE            Short=Toxin-7;
DE   AltName: Full=Toxin II-13.3;
DE   Flags: Fragment;
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, AND FUNCTION.
RC   TISSUE=Venom;
RX   PubMed=7706233; DOI=10.1093/oxfordjournals.jbchem.a124691;
RA   Valdivia H.H., Martin B.M., Ramirez A.N., Fletcher P.L. Jr., Possani L.D.;
RT   "Isolation and pharmacological characterization of four novel Na+ channel-
RT   blocking toxins from the scorpion Centruroides noxius Hoffmann.";
RL   J. Biochem. 116:1383-1391(1994).
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:0000269|PubMed:7706233}.
CC   -!- SUBCELLULAR LOCATION: Secreted.
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 (3 C-C) scorpion toxin superfamily.
CC       Sodium channel inhibitor family. Beta subfamily. {ECO:0000305}.
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DR   AlphaFoldDB; Q9TWL1; -.
DR   SMR; Q9TWL1; -.
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   1: Evidence at protein level;
KW   Direct protein sequencing; Disulfide bond; Ion channel impairing toxin;
KW   Neurotoxin; Secreted; Toxin; Voltage-gated sodium channel impairing toxin.
FT   CHAIN           1..>55
FT                   /note="Beta-toxin Cn7"
FT                   /id="PRO_0000066768"
FT   DOMAIN          1..>55
FT                   /note="LCN-type CS-alpha/beta"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        16..41
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        25..46
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        29..48
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   NON_TER         55
SQ   SEQUENCE   55 AA;  6373 MW;  5A6221630601D25D CRC64;
     KEGYIVNYHD GCKYECYKLG DNDYCLRECK LRVGKGAGGY CYAFACWCTH LYEQA