ID   KAX1D_LEIHE             Reviewed;          37 AA.
AC   P59944;
DT   31-OCT-2003, integrated into UniProtKB/Swiss-Prot.
DT   31-OCT-2003, sequence version 1.
DT   25-MAY-2022, entry version 59.
DE   RecName: Full=Potassium channel toxin alpha-KTx 1.13;
DE   AltName: Full=Charybdotoxin c {ECO:0000303|PubMed:9929387};
DE            Short=ChTx-c {ECO:0000303|PubMed:9929387};
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   PROTEIN SEQUENCE.
RC   TISSUE=Venom;
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).
CC   -!- FUNCTION: Potent selective inhibitor of high conductance (maxi-K),
CC       different medium and small conductance calcium-activated potassium
CC       channels (KCa1.1/KCNMA1 and others), as well as a voltage-dependent
CC       potassium channel (Kv1.3/KCNA3>Kv1.2/KCNA2>Kv1.6/KCNA3>>Shaker/Sh). It
CC       blocks channel activity by a simple bimolecular inhibition process.
CC       {ECO:0000250|UniProtKB:P13487}.
CC   -!- FUNCTION: Has a pH-specific antimicrobial activity against bacteria
CC       (B.subtilis, E.coli and S.aureus) and the fungus C.albicans.
CC       {ECO:0000250|UniProtKB:P13487}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000250|UniProtKB:P13487}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305}.
CC   -!- DOMAIN: Has the structural arrangement of an alpha-helix connected to a
CC       beta-sheet by disulfide bonds (CSalpha/beta).
CC       {ECO:0000250|UniProtKB:P13487}.
CC   -!- SIMILARITY: Belongs to the short scorpion toxin superfamily. Potassium
CC       channel inhibitor family. Alpha-KTx 01 subfamily. {ECO:0000305}.
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DR   AlphaFoldDB; P59944; -.
DR   SMR; P59944; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0008200; F:ion channel inhibitor activity; IEA:InterPro.
DR   GO; GO:0015459; F:potassium channel regulator activity; IEA:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   GO; GO:0042742; P:defense response to bacterium; IEA:UniProtKB-KW.
DR   GO; GO:0050832; P:defense response to fungus; IEA:UniProtKB-KW.
DR   GO; GO:0031640; P:killing of cells of another organism; IEA:UniProtKB-KW.
DR   Gene3D; 3.30.30.10; -; 1.
DR   InterPro; IPR036574; Scorpion_toxin-like_sf.
DR   InterPro; IPR001947; Scorpion_toxinS_K_inh.
DR   Pfam; PF00451; Toxin_2; 1.
DR   PRINTS; PR00286; CHARYBDTOXIN.
DR   SUPFAM; SSF57095; SSF57095; 1.
DR   PROSITE; PS01138; SCORP_SHORT_TOXIN; 1.
PE   1: Evidence at protein level;
KW   Antibiotic; Antimicrobial;
KW   Calcium-activated potassium channel impairing toxin;
KW   Direct protein sequencing; Disulfide bond; Fungicide;
KW   Ion channel impairing toxin; Neurotoxin; Potassium channel impairing toxin;
KW   Pyrrolidone carboxylic acid; Secreted; Toxin;
KW   Voltage-gated potassium channel impairing toxin.
FT   CHAIN           1..37
FT                   /note="Potassium channel toxin alpha-KTx 1.13"
FT                   /id="PRO_0000044892"
FT   REGION          26..33
FT                   /note="Interaction with Ca(2+)-activated K(+) channels"
FT                   /evidence="ECO:0000255"
FT   SITE            27
FT                   /note="Basic residue of the functional dyad"
FT                   /evidence="ECO:0000250"
FT   SITE            36
FT                   /note="Aromatic residue of the functional dyad"
FT                   /evidence="ECO:0000250"
FT   MOD_RES         1
FT                   /note="Pyrrolidone carboxylic acid"
FT                   /evidence="ECO:0000250|UniProtKB:P13487"
FT   DISULFID        7..28
FT                   /evidence="ECO:0000250|UniProtKB:P13487"
FT   DISULFID        13..33
FT                   /evidence="ECO:0000250|UniProtKB:P13487"
FT   DISULFID        17..35
FT                   /evidence="ECO:0000250|UniProtKB:P13487"
SQ   SEQUENCE   37 AA;  4318 MW;  29319BCB43994EE2 CRC64;
     QFTNVSCTTS KECWSVCEKL YNTSRGKCMN KKCRCYS