ID   SIX3_ISOMC              Reviewed;          63 AA.
AC   P0DJK9;
DT   03-APR-2013, integrated into UniProtKB/Swiss-Prot.
DT   03-APR-2013, sequence version 1.
DT   03-AUG-2022, entry version 22.
DE   RecName: Full=Beta-insect depressant toxin Im-3;
OS   Isometrus maculatus (Lesser brown scorpion) (Scorpio maculatus).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Isometrus.
OX   NCBI_TaxID=497827;
RN   [1]
RP   PROTEIN SEQUENCE, FUNCTION, BIOASSAY, AND MASS SPECTROMETRY.
RC   STRAIN=Ishigaki Island; TISSUE=Venom;
RX   PubMed=23291760; DOI=10.1271/bbb.120697;
RA   Kawachi T., Miyashita M., Nakagawa Y., Miyagawa H.;
RT   "Isolation and characterization of an anti-insect beta-toxin from the venom
RT   of the scorpion Isometrus maculatus.";
RL   Biosci. Biotechnol. Biochem. 77:205-207(2013).
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 (By similarity). Induces paralysis in
CC       cricket A.domestica but does not induce death. {ECO:0000250,
CC       ECO:0000269|PubMed:23291760}.
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   -!- MASS SPECTROMETRY: Mass=6894.0; Method=Electrospray; Note=Monoisotopic
CC       mass.; Evidence={ECO:0000269|PubMed:23291760};
CC   -!- MISCELLANEOUS: Does not induce toxicity when intracerebroventricularly
CC       injected into mice. {ECO:0000305|PubMed:23291760}.
CC   -!- SIMILARITY: Belongs to the long (4 C-C) scorpion toxin superfamily.
CC       Sodium channel inhibitor family. Beta subfamily. {ECO:0000305}.
CC   ---------------------------------------------------------------------------
CC   Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC   Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC   ---------------------------------------------------------------------------
DR   AlphaFoldDB; P0DJK9; -.
DR   SMR; P0DJK9; -.
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; Toxin; Voltage-gated sodium channel impairing toxin.
FT   CHAIN           1..63
FT                   /note="Beta-insect depressant toxin Im-3"
FT                   /id="PRO_0000422068"
FT   DOMAIN          1..63
FT                   /note="LCN-type CS-alpha/beta"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        11..63
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        15..37
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        22..44
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        26..46
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
SQ   SEQUENCE   63 AA;  6908 MW;  903DA07877C4F9BE CRC64;
     KEGYGVGKDG CKISCVIGNE FCNKECKYSQ KGTGGYCWTW GLACWCQGLP ENAKVWESST
     NTC