ID   KAX6H_OPICY             Reviewed;          34 AA.
AC   P86116;
DT   05-OCT-2010, integrated into UniProtKB/Swiss-Prot.
DT   24-JUL-2013, sequence version 2.
DT   25-MAY-2022, entry version 28.
DE   RecName: Full=Potassium channel toxin alpha-KTx 6.17;
DE   AltName: Full=Toxin OcyKTx2 {ECO:0000303|PubMed:23684923};
OS   Opisthacanthus cayaporum (South American scorpion).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Iurida; Scorpionoidea; Hemiscorpiidae; Opisthacanthus.
OX   NCBI_TaxID=573324;
RN   [1]
RP   PROTEIN SEQUENCE, FUNCTION, AND MASS SPECTROMETRY.
RC   TISSUE=Venom;
RX   PubMed=23684923; DOI=10.1016/j.peptides.2013.04.021;
RA   Schwartz E.F., Bartok A., Schwartz C.A., Papp F., Gomez-Lagunas F.,
RA   Panyi G., Possani L.D.;
RT   "OcyKTx2, a new K-channel toxin characterized from the venom of the
RT   scorpion Opisthacanthus cayaporum.";
RL   Peptides 46:40-46(2013).
RN   [2]
RP   PROTEIN SEQUENCE OF 1-31, AND MASS SPECTROMETRY.
RC   TISSUE=Venom;
RX   PubMed=18502464; DOI=10.1016/j.toxicon.2008.03.029;
RA   Schwartz E.F., Camargos T.S., Zamudio F.Z., Silva L.P., Bloch C. Jr.,
RA   Caixeta F., Schwartz C.A., Possani L.D.;
RT   "Mass spectrometry analysis, amino acid sequence and biological activity of
RT   venom components from the Brazilian scorpion Opisthacanthus cayaporum.";
RL   Toxicon 51:1499-1508(2008).
CC   -!- FUNCTION: This toxin reversibly blocks Shaker B potassium-channels
CC       (expressed in insect Sf9 cells) with a Kd of 96.6 nM, and presents an
CC       even better affinity toward hKv1.3 (KCNA3), blocking it with a Kd of
CC       17.7 nM. {ECO:0000269|PubMed:23684923}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:18502464}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000269|PubMed:18502464}.
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   -!- MASS SPECTROMETRY: Mass=3807; Method=Electrospray; Note=Monoisotopic
CC       mass.; Evidence={ECO:0000269|PubMed:23684923};
CC   -!- MASS SPECTROMETRY: Mass=3875; Method=Electrospray; Note=mass also found
CC       by MALDI.; Evidence={ECO:0000269|PubMed:18502464};
CC   -!- MISCELLANEOUS: Protein described in PubMed:18502464 elutes at 21.73
CC       min., whereas protein described in PubMed:23684923 elutes at 21.22 min.
CC   -!- SIMILARITY: Belongs to the short scorpion toxin superfamily. Potassium
CC       channel inhibitor family. Alpha-KTx 06 subfamily. {ECO:0000255}.
CC   -!- CAUTION: Peptides from PubMed:23684923 and PubMed:18502464 are
CC       different since they are different in elution time and mass. They are
CC       shown in a single entry until we know the reason of the differences
CC       (eg. sequence or PTMs). {ECO:0000305}.
CC   -!- CAUTION: Peptide described in PubMed:23684923 is identical to AC P86115
CC       in mass and elution time, but not in sequence (2 amino acids are
CC       different). {ECO:0000305}.
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DR   AlphaFoldDB; P86116; -.
DR   SMR; P86116; -.
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   SUPFAM; SSF57095; SSF57095; 1.
DR   PROSITE; PS01138; SCORP_SHORT_TOXIN; 1.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Disulfide bond; Ion channel impairing toxin;
KW   Potassium channel impairing toxin; Secreted; Toxin.
FT   PEPTIDE         1..34
FT                   /note="Potassium channel toxin alpha-KTx 6.17"
FT                   /evidence="ECO:0000269|PubMed:23684923"
FT                   /id="PRO_0000398131"
FT   DISULFID        3..24
FT                   /evidence="ECO:0000250|UniProtKB:Q10726"
FT   DISULFID        9..29
FT                   /evidence="ECO:0000250|UniProtKB:Q10726"
FT   DISULFID        13..31
FT                   /evidence="ECO:0000250|UniProtKB:Q10726"
FT   DISULFID        19..34
FT                   /evidence="ECO:0000250|UniProtKB:Q10726"
SQ   SEQUENCE   34 AA;  3817 MW;  DFA5467C9238613E CRC64;
     IRCQGSNQCY GHCREKTGCM NGKCINRVCK CYGC