ID   KAX35_ANDAU             Reviewed;          59 AA.
AC   P45696;
DT   01-NOV-1995, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1995, sequence version 1.
DT   25-MAY-2022, entry version 92.
DE   RecName: Full=Potassium channel toxin alpha-KTx 3.5;
DE   AltName: Full=Kaliotoxin-2 {ECO:0000303|PubMed:7806508};
DE            Short=KTX-2 {ECO:0000303|PubMed:7806508};
DE   Flags: Precursor;
GN   Name=KTX2;
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], PROTEIN SEQUENCE OF 23-59, AND SUBCELLULAR
RP   LOCATION.
RC   STRAIN=Hector; TISSUE=Venom;
RX   PubMed=7806508; DOI=10.1016/s0021-9258(20)30067-3;
RA   Laraba-Djebari F., Legros C., Crest M., Ceard B., Romi R., Mansuelle P.,
RA   Jacquet G., van Rietschoten J., Gola M., Rochat H.;
RT   "The kaliotoxin family enlarged. Purification, characterization, and
RT   precursor nucleotide sequence of KTX2 from Androctonus australis venom.";
RL   J. Biol. Chem. 269:32835-32843(1994).
RN   [2]
RP   X-RAY CRYSTALLOGRAPHY (1.77 ANGSTROMS) OF 23-59, FUNCTION, AND SYNTHESIS OF
RP   23-59.
RX   PubMed=29483648; DOI=10.1038/s41594-018-0033-9;
RA   Correnti C.E., Gewe M.M., Mehlin C., Bandaranayake A.D., Johnsen W.A.,
RA   Rupert P.B., Brusniak M.Y., Clarke M., Burke S.E., De Van Der Schueren W.,
RA   Pilat K., Turnbaugh S.M., May D., Watson A., Chan M.K., Bahl C.D.,
RA   Olson J.M., Strong R.K.;
RT   "Screening, large-scale production and structure-based classification of
RT   cystine-dense peptides.";
RL   Nat. Struct. Mol. Biol. 25:270-278(2018).
CC   -!- FUNCTION: Has also been shown to inhibit with high potency Kv1.3/KCNA3
CC       and with low potency Kv1.1/KCNA1 and Kv1.2/KCNA2 voltage-gated
CC       potassium channels (PubMed:7806508, PubMed:29483648). Also binds and
CC       inhibits the molluscan calcium-activated potassium channels KCa (Kd=135
CC       nM) (PubMed:7806508). {ECO:0000269|PubMed:29483648,
CC       ECO:0000269|PubMed:7806508}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:7806508}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000305|PubMed:7806508}.
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 short scorpion toxin superfamily. Potassium
CC       channel inhibitor family. Alpha-KTx 03 subfamily. {ECO:0000305}.
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DR   EMBL; S74733; AAB33535.1; -; mRNA.
DR   PIR; A55807; A55807.
DR   PDB; 6AY7; X-ray; 1.77 A; A/B=23-59.
DR   PDBsum; 6AY7; -.
DR   AlphaFoldDB; P45696; -.
DR   SMR; P45696; -.
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   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   3D-structure; Calcium-activated potassium channel impairing toxin;
KW   Direct protein sequencing; Disulfide bond; Ion channel impairing toxin;
KW   Neurotoxin; Potassium channel impairing toxin; Secreted; Signal; Toxin.
FT   SIGNAL          1..22
FT                   /evidence="ECO:0000269|PubMed:7806508"
FT   CHAIN           23..59
FT                   /note="Potassium channel toxin alpha-KTx 3.5"
FT                   /id="PRO_0000035312"
FT   REGION          47..54
FT                   /note="Interaction with Ca(2+)-activated K(+) channels"
FT                   /evidence="ECO:0000255"
FT   DISULFID        29..49
FT                   /evidence="ECO:0000269|PubMed:29483648,
FT                   ECO:0000312|PDB:6AY7"
FT   DISULFID        35..54
FT                   /evidence="ECO:0000269|PubMed:29483648,
FT                   ECO:0000312|PDB:6AY7"
FT   DISULFID        39..56
FT                   /evidence="ECO:0000269|PubMed:29483648,
FT                   ECO:0000312|PDB:6AY7"
FT   STRAND          23..28
FT                   /evidence="ECO:0007829|PDB:6AY7"
FT   HELIX           32..35
FT                   /evidence="ECO:0007829|PDB:6AY7"
FT   HELIX           36..41
FT                   /evidence="ECO:0007829|PDB:6AY7"
FT   STRAND          45..50
FT                   /evidence="ECO:0007829|PDB:6AY7"
FT   STRAND          53..57
FT                   /evidence="ECO:0007829|PDB:6AY7"
SQ   SEQUENCE   59 AA;  6393 MW;  DD3225C5D270EB26 CRC64;
     MKVFSAVLII LFVCSMIIGI NAVRIPVSCK HSGQCLKPCK DAGMRFGKCM NGKCDCTPK