ID   SIX2_HOTJU              Reviewed;          85 AA.
AC   P24336;
DT   01-MAR-1992, integrated into UniProtKB/Swiss-Prot.
DT   01-MAR-1992, sequence version 1.
DT   03-AUG-2022, entry version 95.
DE   RecName: Full=Beta-insect depressant toxin BjIT2;
DE            Short=IT-2;
DE   Flags: Precursor;
OS   Hottentotta judaicus (Black scorpion) (Buthotus judaicus).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Hottentotta.
OX   NCBI_TaxID=6863;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RX   PubMed=1796479; DOI=10.1016/0041-0101(91)90213-b;
RA   Zilberberg N., Zlotkin E., Gurevitz M.;
RT   "The cDNA sequence of a depressant insect selective neurotoxin from the
RT   scorpion Buthotus judaicus.";
RL   Toxicon 29:1155-1158(1991).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RX   PubMed=8431601; DOI=10.1002/arch.940220107;
RA   Zlotkin E., Gurevitz M., Fowler E., Adams M.E.;
RT   "Depressant insect selective neurotoxins from scorpion venom: chemistry,
RT   action, and gene cloning.";
RL   Arch. Insect Biochem. Physiol. 22:55-73(1993).
RN   [3]
RP   PROTEIN SEQUENCE OF 22-82.
RC   TISSUE=Venom;
RA   Zlotkin E., Fowler E., Eitan M., Moyer M., Adams M.E.;
RT   "On the chemistry and action of the depressant insect toxins.";
RL   Toxicon 28:170-170(1990).
RN   [4]
RP   PROTEIN SEQUENCE OF 22-82, AND CHARACTERIZATION.
RC   TISSUE=Venom;
RX   PubMed=2029523; DOI=10.1021/bi00233a025;
RA   Zlotkin E., Eitan M., Bindokas V.P., Adams M.E., Moyer M., Burkhart W.,
RA   Fowler E.;
RT   "Functional duality and structural uniqueness of depressant insect-
RT   selective neurotoxins.";
RL   Biochemistry 30:4814-4821(1991).
CC   -!- FUNCTION: Depressant insect beta-toxins cause a transient contraction
CC       paralysis followed by a slow flaccid paralysis. They bind voltage-
CC       independently at site-4 of sodium channels (Nav) and shift the voltage
CC       of activation toward more negative potentials thereby affecting sodium
CC       channel activation and promoting spontaneous and repetitive firing.
CC       This toxin is active only 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   -!- PTM: C-terminal basic residues are removed by a carboxypeptidase.
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; S55535; AAB25385.1; -; mRNA.
DR   PIR; A40472; A40472.
DR   AlphaFoldDB; P24336; -.
DR   SMR; P24336; -.
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   CDD; cd00107; Knot1; 1.
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; Signal; Toxin;
KW   Voltage-gated sodium channel impairing toxin.
FT   SIGNAL          1..21
FT                   /evidence="ECO:0000269|PubMed:2029523, ECO:0000269|Ref.3"
FT   CHAIN           22..82
FT                   /note="Beta-insect depressant toxin BjIT2"
FT                   /id="PRO_0000035197"
FT   PROPEP          83..85
FT                   /note="Removed by a carboxypeptidase"
FT                   /id="PRO_0000035198"
FT   DOMAIN          22..82
FT                   /note="LCN-type CS-alpha/beta"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        31..81
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        35..56
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        42..63
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        46..65
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
SQ   SEQUENCE   85 AA;  9349 MW;  7E8CE58BBD211EB6 CRC64;
     MKLLLLLVIS ASMLLECLVN ADGYIRKKDG CKVSCIIGNE GCRKECVAHG GSFGYCWTWG
     LACWCENLPD AVTWKSSTNT CGRKK