ID   KA181_TITOB             Reviewed;          61 AA.
AC   P60211; A0A1E1WVW1;
DT   16-JAN-2004, integrated into UniProtKB/Swiss-Prot.
DT   25-MAY-2022, sequence version 2.
DT   03-AUG-2022, entry version 61.
DE   RecName: Full=Potassium channel toxin alpha-KTx 18.1;
DE   AltName: Full=Toxin Tc32 {ECO:0000303|PubMed:12445473};
DE   AltName: Full=Toxin To32 {ECO:0000305};
DE   Flags: Precursor;
OS   Tityus obscurus (Amazonian scorpion) (Tityus cambridgei).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Tityus.
OX   NCBI_TaxID=1221240;
RN   [1] {ECO:0000312|EMBL:JAT91155.1}
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   TISSUE=Telson;
RX   PubMed=29561852; DOI=10.1371/journal.pone.0193739;
RA   de Oliveira U.C., Nishiyama M.Y. Jr., Dos Santos M.B.V.,
RA   Santos-da-Silva A.P., Chalkidis H.M., Souza-Imberg A., Candido D.M.,
RA   Yamanouye N., Dorce V.A.C., Junqueira-de-Azevedo I.L.M.;
RT   "Proteomic endorsed transcriptomic profiles of venom glands from Tityus
RT   obscurus and T. serrulatus scorpions.";
RL   PLoS ONE 13:e0193739-e0193739(2018).
RN   [2]
RP   PROTEIN SEQUENCE OF 25-61, FUNCTION, MASS SPECTROMETRY, AND 3D-STRUCTURE
RP   MODELING.
RC   TISSUE=Venom;
RX   PubMed=12445473; DOI=10.1016/s1570-9639(02)00458-2;
RA   Batista C.V.F., Gomez-Lagunas F., Rodriguez de la Vega R.C., Hajdu P.,
RA   Panyi G., Gaspar R., Possani L.D.;
RT   "Two novel toxins from the Amazonian scorpion Tityus cambridgei that block
RT   Kv1.3 and Shaker B K(+)-channels with distinctly different affinities.";
RL   Biochim. Biophys. Acta 1601:123-131(2002).
RN   [3]
RP   PROTEIN SEQUENCE OF 25-36, SUBCELLULAR LOCATION, AND MASS SPECTROMETRY.
RC   TISSUE=Venom;
RX   PubMed=15025998; DOI=10.1016/j.jchromb.2003.09.002;
RA   Batista C.V.F., del Pozo L., Zamudio F.Z., Contreras S., Becerril B.,
RA   Wanke E., Possani L.D.;
RT   "Proteomics of the venom from the Amazonian scorpion Tityus cambridgei and
RT   the role of prolines on mass spectrometry analysis of toxins.";
RL   J. Chromatogr. B 803:55-66(2004).
RN   [4]
RP   STRUCTURE BY NMR OF 25-61, AND DISULFIDE BOND.
RX   PubMed=22332965; DOI=10.1021/bi201713z;
RA   Stehling E.G., Sforca M.L., Zanchin N.I., Oyama S. Jr., Pignatelli A.,
RA   Belluzzi O., Polverini E., Corsini R., Spisni A., Pertinhez T.A.;
RT   "Looking over toxin-K(+) channel interactions. Clues from the structural
RT   and functional characterization of alpha-KTx toxin Tc32, a Kv1.3 channel
RT   blocker.";
RL   Biochemistry 51:1885-1894(2012).
CC   -!- FUNCTION: Reversible blocker of both Kv1.3/KCNA3 potassium channels
CC       (high affinity) and Shaker B (mammalian Kv1.1 analog) potassium
CC       channels (very low affinity). {ECO:0000269|PubMed:12445473}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:15025998}.
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:0000305|PubMed:22332965}.
CC   -!- MASS SPECTROMETRY: Mass=3521.5; Method=Electrospray;
CC       Evidence={ECO:0000269|PubMed:12445473, ECO:0000269|PubMed:15025998};
CC   -!- SIMILARITY: Belongs to the short scorpion toxin superfamily. Potassium
CC       channel inhibitor family. Alpha-KTx 18 subfamily. {ECO:0000305}.
CC   -!- CAUTION: Lacks the dyad motif characteristic of alpha-KTx and generally
CC       associated with channel blockage. {ECO:0000305}.
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DR   EMBL; GEMQ01000034; JAT91155.1; -; mRNA.
DR   PDB; 2JP6; NMR; -; A=27-61.
DR   PDBsum; 2JP6; -.
DR   AlphaFoldDB; P60211; -.
DR   BMRB; P60211; -.
DR   SMR; P60211; -.
DR   EvolutionaryTrace; P60211; -.
DR   GO; GO:0005576; C:extracellular region; HDA:UniProtKB.
DR   GO; GO:0019870; F:potassium channel inhibitor activity; IDA:UniProtKB.
DR   GO; GO:0090729; F:toxin activity; IDA:UniProtKB.
DR   GO; GO:0044361; P:negative regulation of voltage-gated potassium channel activity in another organism; IDA:UniProtKB.
PE   1: Evidence at protein level;
KW   3D-structure; Direct protein sequencing; Disulfide bond;
KW   Ion channel impairing toxin; Neurotoxin; Potassium channel impairing toxin;
KW   Secreted; Signal; Toxin; Voltage-gated potassium channel impairing toxin.
FT   SIGNAL          1..24
FT                   /evidence="ECO:0000255"
FT   PEPTIDE         25..61
FT                   /note="Potassium channel toxin alpha-KTx 18.1"
FT                   /evidence="ECO:0000269|PubMed:12445473"
FT                   /id="PRO_0000044921"
FT   SITE            60
FT                   /note="Penetrates into Kv pores (more deeply into Kv1.3
FT                   than into Kv1.1)"
FT                   /evidence="ECO:0000305|PubMed:22332965"
FT   DISULFID        33..52
FT                   /evidence="ECO:0000269|PubMed:22332965"
FT   DISULFID        38..57
FT                   /evidence="ECO:0000269|PubMed:22332965"
FT   DISULFID        42..59
FT                   /evidence="ECO:0000269|PubMed:22332965"
FT   STRAND          1..3
FT                   /evidence="ECO:0007829|PDB:2JP6"
FT   HELIX           10..19
FT                   /evidence="ECO:0007829|PDB:2JP6"
FT   STRAND          21..24
FT                   /evidence="ECO:0007829|PDB:2JP6"
FT   STRAND          26..29
FT                   /evidence="ECO:0007829|PDB:2JP6"
FT   STRAND          32..34
FT                   /evidence="ECO:0007829|PDB:2JP6"
SQ   SEQUENCE   61 AA;  6530 MW;  D1ACB357B32252E7 CRC64;
     MRFTGIILIL ISMTLIDSFF EMKVEATGPQ TTCQAAMCEA GCKGLGKSME SCQGDTCKCK
     A