ID   SIX2_ANDAU              Reviewed;          88 AA.
AC   P15147;
DT   01-APR-1990, integrated into UniProtKB/Swiss-Prot.
DT   01-APR-1990, sequence version 1.
DT   25-MAY-2022, entry version 99.
DE   RecName: Full=Beta-insect excitatory toxin 2;
DE   AltName: Full=AaH IT2 {ECO:0000303|PubMed:2808423};
DE            Short=AaHIT2;
DE            Short=AaIT2;
DE   Flags: Precursor;
OS   Androctonus australis (Sahara scorpion).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Androctonus.
OX   NCBI_TaxID=6858;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   STRAIN=Hector; TISSUE=Venom gland;
RX   PubMed=2808423; DOI=10.1016/s0021-9258(19)47295-5;
RA   Bougis P.E., Rochat H., Smith L.A.;
RT   "Precursors of Androctonus australis scorpion neurotoxins. Structures of
RT   precursors, processing outcomes, and expression of a functional recombinant
RT   toxin II.";
RL   J. Biol. Chem. 264:19259-19265(1989).
RN   [2]
RP   PROTEIN SEQUENCE OF 19-88, AND SUBCELLULAR LOCATION.
RC   STRAIN=Hector; TISSUE=Venom;
RX   PubMed=2334710; DOI=10.1021/bi00458a021;
RA   Loret E.P., Mansuelle P., Rochat H., Granier C.;
RT   "Neurotoxins active on insects: amino acid sequences, chemical
RT   modifications, and secondary structure estimation by circular dichroism of
RT   toxins from the scorpion Androctonus australis hector.";
RL   Biochemistry 29:1492-1501(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. This toxin is active only on insects.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:2808423}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000305|PubMed:2808423}.
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   EMBL; M27707; AAA29952.1; -; mRNA.
DR   PIR; G34444; G34444.
DR   AlphaFoldDB; P15147; -.
DR   SMR; P15147; -.
DR   PRIDE; P15147; -.
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; Signal; Toxin;
KW   Voltage-gated sodium channel impairing toxin.
FT   SIGNAL          1..18
FT                   /evidence="ECO:0000305|PubMed:2334710"
FT   CHAIN           19..88
FT                   /note="Beta-insect excitatory toxin 2"
FT                   /evidence="ECO:0000269|PubMed:2334710"
FT                   /id="PRO_0000035188"
FT   DOMAIN          20..83
FT                   /note="LCN-type CS-alpha/beta"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01210"
FT   DISULFID        34..55
FT                   /evidence="ECO:0000250|UniProtKB:P56637"
FT   DISULFID        40..60
FT                   /evidence="ECO:0000250|UniProtKB:P56637"
FT   DISULFID        44..62
FT                   /evidence="ECO:0000250|UniProtKB:P56637"
FT   DISULFID        56..82
FT                   /evidence="ECO:0000250|UniProtKB:P56637"
FT   CONFLICT        21
FT                   /note="N -> D (in Ref. 2; AA sequence)"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   88 AA;  9863 MW;  81EBC38750777492 CRC64;
     MKFLLLFLVV LPIMGVLGKK NGYAVDSSGK APECLLSNYC YNECTKVHYA DKGYCCLLSC
     YCFGLNDDKK VLEISDTRKS YCDTPIIN