ID   SCX2_MESEU              Reviewed;          62 AA.
AC   P15221;
DT   01-APR-1990, integrated into UniProtKB/Swiss-Prot.
DT   01-APR-1990, sequence version 1.
DT   25-MAY-2022, entry version 75.
DE   RecName: Full=Toxin BeI2;
DE   AltName: Full=Insectotoxin I2;
OS   Mesobuthus eupeus (Lesser Asian scorpion) (Buthus eupeus).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Mesobuthus.
OX   NCBI_TaxID=34648;
RN   [1]
RP   PROTEIN SEQUENCE.
RC   TISSUE=Venom;
RA   Grishin E.V., Soldatova L.N., Soldatov N.M., Kostetsky P.V.,
RA   Ovchinnikov Y.A.;
RT   "Amino acid sequence of insectotoxin I2 from central Asia scorpion Buthus
RT   eupeus venom.";
RL   Bioorg. Khim. 5:1285-1294(1979).
CC   -!- FUNCTION: Binds to sodium channels (Nav) and inhibits the inactivation
CC       of the activated channels, thereby blocking neuronal transmission. This
CC       toxin is active on insects.
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. Alpha subfamily. {ECO:0000305}.
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DR   PIR; JN0384; JN0384.
DR   AlphaFoldDB; P15221; -.
DR   SMR; P15221; -.
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   Direct protein sequencing; Disulfide bond; Ion channel impairing toxin;
KW   Neurotoxin; Secreted; Toxin; Voltage-gated sodium channel impairing toxin.
FT   CHAIN           1..62
FT                   /note="Toxin BeI2"
FT                   /id="PRO_0000066728"
FT   DOMAIN          1..62
FT                   /note="LCN-type CS-alpha/beta"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        11..62
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        15..37
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        22..45
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        26..47
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
SQ   SEQUENCE   62 AA;  6855 MW;  8556F9E97F8AA763 CRC64;
     ADGYVKGKSG CKISCFLDND LCNADCKYYG GKLNSWCIPD KSGYCWCPNK GWNSIKSETN
     TC