ID   SCE3_CENSC              Reviewed;          87 AA.
AC   Q95WD2;
DT   16-APR-2002, integrated into UniProtKB/Swiss-Prot.
DT   01-DEC-2001, sequence version 1.
DT   03-AUG-2022, entry version 78.
DE   RecName: Full=Beta-toxin CsE3;
DE   AltName: Full=Neurotoxin E3;
DE   Flags: Precursor;
OS   Centruroides sculpturatus (Arizona bark scorpion).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Centruroides.
OX   NCBI_TaxID=218467;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   TISSUE=Venom gland;
RX   PubMed=11600153; DOI=10.1016/s0041-0101(01)00174-x;
RA   Corona M., Valdez-Cruz N.A., Merino E., Zurita M., Possani L.D.;
RT   "Genes and peptides from the scorpion Centruroides sculpturatus Ewing, that
RT   recognize Na(+)-channels.";
RL   Toxicon 39:1893-1898(2001).
RN   [2]
RP   REVIEW, AND FUNCTION.
RX   PubMed=16274721; DOI=10.1016/j.toxicon.2005.09.006;
RA   Rodriguez de la Vega R.C., Possani L.D.;
RT   "Overview of scorpion toxins specific for Na+ channels and related
RT   peptides: biodiversity, structure-function relationships and evolution.";
RL   Toxicon 46:831-844(2005).
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:16274721}.
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 (4 C-C) scorpion toxin superfamily.
CC       Sodium channel inhibitor family. Beta subfamily. {ECO:0000305}.
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DR   EMBL; AF338449; AAL23417.1; -; mRNA.
DR   AlphaFoldDB; Q95WD2; -.
DR   SMR; Q95WD2; -.
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..19
FT   CHAIN           20..85
FT                   /note="Beta-toxin CsE3"
FT                   /id="PRO_0000035293"
FT   DOMAIN          20..85
FT                   /note="LCN-type CS-alpha/beta"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   MOD_RES         85
FT                   /note="Asparagine amide"
FT                   /evidence="ECO:0000250"
FT   DISULFID        31..84
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        35..60
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        44..65
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        48..67
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
SQ   SEQUENCE   87 AA;  9818 MW;  BC1F690F5E67AA11 CRC64;
     MNSLLIIAAC LALIGTVWAK EGYIVNYHTG CKYECFKLGD NDYCLRECKL RHGKGSGGYC
     YAFGCWCTHL YEQAVVWPLP KKKCNGK