ID   TOT2B_ATRIL             Reviewed;         100 AA.
AC   Q9BJV7;
DT   23-JAN-2002, integrated into UniProtKB/Swiss-Prot.
DT   01-JUN-2001, sequence version 1.
DT   25-MAY-2022, entry version 73.
DE   RecName: Full=Omega-hexatoxin-Asp2b;
DE            Short=Omega-HXTX-Asp2b;
DE   AltName: Full=Omega-atracotoxin-As2b;
DE            Short=Omega-AcTx-As2b;
DE   Flags: Precursor;
OS   Atrax sp. (strain Illawarra) (Funnel-web spider).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida; Araneae;
OC   Mygalomorphae; Hexathelidae; Atrax; unclassified Atrax.
OX   NCBI_TaxID=153482;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   TISSUE=Venom gland;
RX   PubMed=11522785; DOI=10.1074/jbc.m105206200;
RA   Wang X.-H., Connor M., Wilson D., Wilson H.I., Nicholson G.M., Smith R.,
RA   Shaw D., Mackay J.P., Alewood P.F., Christie M.J., King G.F.;
RT   "Discovery and structure of a potent and highly specific blocker of insect
RT   calcium channels.";
RL   J. Biol. Chem. 276:40306-40312(2001).
CC   -!- FUNCTION: Potent inhibitor of insect, but not mammalian, voltage-gated
CC       calcium channels (Cav). {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Secreted.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC   -!- DOMAIN: The presence of a 'disulfide through disulfide knot'
CC       structurally defines this protein as a knottin. {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the neurotoxin 15 family. 02 (omega-actx)
CC       subfamily. {ECO:0000305}.
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DR   EMBL; AF329445; AAK17948.1; -; mRNA.
DR   AlphaFoldDB; Q9BJV7; -.
DR   ArachnoServer; AS000205; omega-hexatoxin-Asp2b.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0005246; F:calcium channel regulator activity; IEA:UniProtKB-KW.
DR   GO; GO:0019871; F:sodium channel inhibitor activity; IEA:InterPro.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   InterPro; IPR013139; Omega_atracotoxin_CS2.
DR   InterPro; IPR012628; Toxin_23.
DR   Pfam; PF08093; Toxin_23; 1.
DR   PROSITE; PS60017; OMEGA_ACTX_2; 1.
PE   2: Evidence at transcript level;
KW   Calcium channel impairing toxin; Disulfide bond;
KW   Ion channel impairing toxin; Knottin; Neurotoxin; Secreted; Signal; Toxin;
KW   Voltage-gated calcium channel impairing toxin.
FT   SIGNAL          1..23
FT                   /evidence="ECO:0000255"
FT   PROPEP          24..55
FT                   /evidence="ECO:0000250"
FT                   /id="PRO_0000035553"
FT   CHAIN           56..100
FT                   /note="Omega-hexatoxin-Asp2b"
FT                   /id="PRO_0000035554"
FT   DISULFID        60..73
FT                   /evidence="ECO:0000250"
FT   DISULFID        66..79
FT                   /evidence="ECO:0000250"
FT   DISULFID        72..84
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   100 AA;  10587 MW;  D8D66876D0316F95 CRC64;
     MKFSKLSITL AVILTQAVFV LCGMKNEDFM EKGLESNELH DAIKKPVNSG KPDTERLLDC
     VLSRVCSSDA NCCGLTPTCK MGLCVPKVGG LLGGLLGGIL