ID   SIX1_LEIQU              Reviewed;          70 AA.
AC   P19856;
DT   01-FEB-1991, integrated into UniProtKB/Swiss-Prot.
DT   01-FEB-1991, sequence version 1.
DT   25-MAY-2022, entry version 87.
DE   RecName: Full=Beta-insect excitatory toxin LqqIT1;
DE            Short=Insect toxin 1;
DE            Short=LqqIT1';
OS   Leiurus quinquestriatus quinquestriatus (Egyptian scorpion) (Deathstalker
OS   scorpion).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Leiurus.
OX   NCBI_TaxID=6885;
RN   [1]
RP   PROTEIN SEQUENCE, FUNCTION, SUBCELLULAR LOCATION, AND BIOASSAY.
RC   TISSUE=Venom;
RX   PubMed=2311768; DOI=10.1016/0014-5793(90)80607-k;
RA   Kopeyan C., Mansuelle P., Sampieri F., Brando T., Bahraoui E.M., Rochat H.,
RA   Granier C.;
RT   "Primary structure of scorpion anti-insect toxins isolated from the venom
RT   of Leiurus quinquestriatus quinquestriatus.";
RL   FEBS Lett. 261:423-426(1990).
CC   -!- FUNCTION: Excitatory insect beta-toxins induce a spastic paralysis.
CC       They bind voltage-independently at site-4 of sodium channels (Nav) and
CC       shift the voltage of activation toward more negative potentials thereby
CC       affecting sodium channel activation and promoting spontaneous and
CC       repetitive firing. In vivo, this toxin induces a fast excitatory
CC       contraction paralysis on fly larvae (PubMed:2311768). It is active only
CC       on insects (PubMed:2311768). {ECO:0000269|PubMed:2311768}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:2311768}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000305|PubMed:2311768}.
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   PIR; S08267; S08267.
DR   AlphaFoldDB; P19856; -.
DR   SMR; P19856; -.
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; IPR002061; Scorpion_toxinL/defensin.
DR   Pfam; PF00537; Toxin_3; 1.
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..70
FT                   /note="Beta-insect excitatory toxin LqqIT1"
FT                   /evidence="ECO:0000269|PubMed:2311768"
FT                   /id="PRO_0000066711"
FT   DOMAIN          2..65
FT                   /note="LCN-type CS-alpha/beta"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        16..37
FT                   /evidence="ECO:0000250|UniProtKB:P56637"
FT   DISULFID        22..42
FT                   /evidence="ECO:0000250|UniProtKB:P56637"
FT   DISULFID        26..44
FT                   /evidence="ECO:0000250|UniProtKB:P56637"
FT   DISULFID        38..64
FT                   /evidence="ECO:0000250|UniProtKB:P56637"
FT   VARIANT         33
FT                   /note="D -> E (in LqqIT1')"
SQ   SEQUENCE   70 AA;  7849 MW;  341B27A700BCB6C7 CRC64;
     KKNGYAVDSS GKAPECLLSN YCYNECTKVH YADKGYCCLL SCYCVGLSDD KKVLEISDAR
     KKYCDFVTIN