ID   KA143_MESMA             Reviewed;          54 AA.
AC   Q9BJX2; Q549F1;
DT   26-SEP-2003, integrated into UniProtKB/Swiss-Prot.
DT   01-JUN-2001, sequence version 1.
DT   25-MAY-2022, entry version 67.
DE   RecName: Full=Potassium channel toxin alpha-KTx 14.3;
DE   AltName: Full=BmKK3;
DE            Short=Kk3;
DE   AltName: Full=Neurotoxin SKTx2;
DE   AltName: Full=Toxin KK2;
DE   Flags: Precursor;
OS   Mesobuthus martensii (Manchurian scorpion) (Buthus martensii).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Mesobuthus.
OX   NCBI_TaxID=34649;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   TISSUE=Venom gland;
RX   PubMed=11698110; DOI=10.1016/s0300-9084(01)01326-8;
RA   Zeng X.-C., Peng F., Luo F., Zhu S.-Y., Liu H., Li W.-X.;
RT   "Molecular cloning and characterization of four scorpion K(+)-toxin-like
RT   peptides: a new subfamily of venom peptides (alpha-KTx14) and genomic
RT   analysis of a member.";
RL   Biochimie 83:883-889(2001).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RA   Xu C.-Q., Chi C.-W.;
RT   "A novel subfamily of potassium channel toxins from Buthus martensii
RT   Karsch.";
RL   Submitted (NOV-2000) to the EMBL/GenBank/DDBJ databases.
RN   [3]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   TISSUE=Venom gland;
RA   Li W.-X., Zeng X.-C., Zhu S.-Y.;
RT   "A complete cDNA sequence encoding the precursor of a novel toxin (named
RT   KK2) active on potassium channels cloned from Buthus martensii Karsch.";
RL   Submitted (MAR-1999) to the EMBL/GenBank/DDBJ databases.
RN   [4]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RA   Zeng X.-C., Zhang L., Luo X., Cao H.;
RT   "Positive natural selection has driven the intron gain for the K+-channel
RT   specific toxin genes from the scorpion Mesobuthus martensii Karsch.";
RL   Submitted (MAR-2012) to the EMBL/GenBank/DDBJ databases.
RN   [5]
RP   PROTEIN SEQUENCE OF 24-29, SUBCELLULAR LOCATION, AND MASS SPECTROMETRY.
RC   TISSUE=Venom;
RX   PubMed=22887697; DOI=10.1002/pmic.201200224;
RA   Xu J., Zhang X., Guo Z., Yan J., Yu L., Li X., Xue X., Liang X.;
RT   "Short-chain peptides identification of scorpion Buthus martensi Karsch
RT   venom by employing high orthogonal 2D-HPLC system and tandem mass
RT   spectrometry.";
RL   Proteomics 12:3076-3084(2012).
CC   -!- FUNCTION: Potential blocker of potassium channels.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:22887697}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305}.
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   -!- PTM: Contains 3 disulfide bridges. {ECO:0000250}.
CC   -!- MASS SPECTROMETRY: Mass=3313.46; Method=Electrospray; Note=Monoisotopic
CC       mass.; Evidence={ECO:0000269|PubMed:22887697};
CC   -!- SIMILARITY: Belongs to the short scorpion toxin superfamily. Potassium
CC       channel inhibitor family. Alpha-KTx 14 subfamily. {ECO:0000305}.
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DR   EMBL; AJ277728; CAC38037.1; -; mRNA.
DR   EMBL; AF325113; AAK33068.1; -; mRNA.
DR   EMBL; AF135818; AAQ13567.1; -; mRNA.
DR   EMBL; JQ738413; AFR43619.1; -; Genomic_DNA.
DR   PIR; A59321; A59321.
DR   PIR; A59357; A59357.
DR   AlphaFoldDB; Q9BJX2; -.
DR   SMR; Q9BJX2; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0015459; F:potassium channel regulator activity; IEA:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   InterPro; IPR036574; Scorpion_toxin-like_sf.
DR   SUPFAM; SSF57095; SSF57095; 1.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Disulfide bond; Ion channel impairing toxin;
KW   Neurotoxin; Potassium channel impairing toxin; Secreted; Signal; Toxin.
FT   SIGNAL          1..23
FT                   /evidence="ECO:0000269|PubMed:22887697"
FT   CHAIN           24..54
FT                   /note="Potassium channel toxin alpha-KTx 14.3"
FT                   /id="PRO_0000035335"
SQ   SEQUENCE   54 AA;  5858 MW;  AF41E6337299C5C1 CRC64;
     MKIFFAILLI LAVCSMAIWT VNGTPFEVRC ATDADCSRKC PGNPPCRNGF CACT