ID   SX25_LEIHE              Reviewed;          85 AA.
AC   P68726;
DT   07-DEC-2004, integrated into UniProtKB/Swiss-Prot.
DT   07-DEC-2004, sequence version 1.
DT   03-AUG-2022, entry version 61.
DE   RecName: Full=Insect toxin 2-53;
DE   AltName: Full=LqhIT2-53;
DE   Flags: Precursor;
OS   Leiurus hebraeus (Deathstalker scorpion) (Leiurus quinquestriatus
OS   hebraeus).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Leiurus.
OX   NCBI_TaxID=6884;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=9929387; DOI=10.1007/pl00006457;
RA   Froy O., Sagiv T., Poreh M., Urbach D., Zilberberg N., Gurevitz M.;
RT   "Dynamic diversification from a putative common ancestor of scorpion toxins
RT   affecting sodium, potassium, and chloride channels.";
RL   J. Mol. Evol. 48:187-196(1999).
RN   [2]
RP   IDENTIFICATION BY MASS SPECTROMETRY.
RX   PubMed=16551474; DOI=10.1016/j.toxicon.2006.01.015;
RA   Nascimento D.G., Rates B., Santos D.M., Verano-Braga T., Barbosa-Silva A.,
RA   Dutra A.A.A., Biondi I., Martin-Eauclaire M.-F., De Lima M.E.,
RA   Pimenta A.M.C.;
RT   "Moving pieces in a taxonomic puzzle: venom 2D-LC/MS and data clustering
RT   analyses to infer phylogenetic relationships in some scorpions from the
RT   Buthidae family (Scorpiones).";
RL   Toxicon 47:628-639(2006).
CC   -!- FUNCTION: Depressant insect toxins cause a transient contraction
CC       paralysis followed by a slow flaccid paralysis. They bind voltage-
CC       independently to sodium channels (Nav) and block action potentials,
CC       primarily by depolarizing the axonal membrane and suppressing the
CC       sodium current (By similarity). {ECO:0000250}.
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   AlphaFoldDB; P68726; -.
DR   SMR; P68726; -.
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   Amidation; Disulfide bond; Ion channel impairing toxin; Neurotoxin;
KW   Secreted; Signal; Toxin; Voltage-gated sodium channel impairing toxin.
FT   SIGNAL          1..21
FT                   /evidence="ECO:0000250"
FT   CHAIN           22..82
FT                   /note="Insect toxin 2-53"
FT                   /id="PRO_0000035195"
FT   DOMAIN          22..82
FT                   /note="LCN-type CS-alpha/beta"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   MOD_RES         82
FT                   /note="Glycine amide"
FT                   /evidence="ECO:0000250"
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;  9320 MW;  D8C5561177079297 CRC64;
     MKLLLLLIVS ASMLIESLVN ADGYIKRRDG CKVACLVGNE GCDKECKAYG GSYGYCWTWG
     LACWCEGLPD DKTWKSETNT CGGKK