ID   KA261_MESMA             Reviewed;          57 AA.
AC   A7KJJ7;
DT   11-JAN-2011, integrated into UniProtKB/Swiss-Prot.
DT   11-SEP-2007, sequence version 1.
DT   25-MAY-2022, entry version 43.
DE   RecName: Full=Potassium channel toxin alpha-KTx 26.1 {ECO:0000303|PubMed:17624312};
DE   AltName: Full=Neurotoxin BmK86 {ECO:0000303|PubMed:17624312};
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], FUNCTION, AND TISSUE SPECIFICITY.
RC   TISSUE=Venom gland;
RX   PubMed=17624312; DOI=10.1016/j.bbrc.2007.06.108;
RA   Mao X., Cao Z.-J., Yin S.-J., Ma Y., Wu Y.-L., Li W.-X.;
RT   "Cloning and characterization of BmK86, a novel K(+)-channel blocker from
RT   scorpion venom.";
RL   Biochem. Biophys. Res. Commun. 360:728-734(2007).
RN   [2]
RP   FUNCTION, AND SYNTHESIS OF 23-57.
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: Recombinant toxin that reversibly inhibits the potassium
CC       current of mKv1.3/KCNA3 channel stably expressed in COS7 cells
CC       (IC(50)=150 nM) (PubMed:17624312). Also shows a weak inhibition on
CC       Kv1.2/KCNA2, Kv1.3/KCNA3 and TRPV1 channels (PubMed:29483648).
CC       {ECO:0000269|PubMed:17624312, ECO:0000269|PubMed:29483648}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000305|PubMed:17624312}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000305|PubMed:17624312}.
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:P0DL65}.
CC   -!- MISCELLANEOUS: Does not inhibit large conductance calcium-activated
CC       potassium channels (BK). {ECO:0000269|PubMed:17624312}.
CC   -!- SIMILARITY: Belongs to the short scorpion toxin superfamily. Potassium
CC       channel inhibitor family. Alpha-KTx 26 subfamily. {ECO:0000305}.
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DR   EMBL; EF457939; ABR14604.1; -; mRNA.
DR   AlphaFoldDB; A7KJJ7; -.
DR   SMR; A7KJJ7; -.
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   2: Evidence at transcript level;
KW   Disulfide bond; Ion channel impairing toxin; Neurotoxin;
KW   Potassium channel impairing toxin; Secreted; Signal; Toxin;
KW   Voltage-gated potassium channel impairing toxin.
FT   SIGNAL          1..22
FT                   /evidence="ECO:0000255"
FT   CHAIN           23..57
FT                   /note="Potassium channel toxin alpha-KTx 26.1"
FT                   /id="PRO_0000403831"
FT   SITE            47
FT                   /note="Basic residue of the functional dyad"
FT                   /evidence="ECO:0000305"
FT   SITE            56
FT                   /note="Aromatic residue of the functional dyad"
FT                   /evidence="ECO:0000305"
FT   DISULFID        30..48
FT                   /evidence="ECO:0000250|UniProtKB:P0DL65"
FT   DISULFID        34..53
FT                   /evidence="ECO:0000250|UniProtKB:P0DL65"
FT   DISULFID        38..55
FT                   /evidence="ECO:0000250|UniProtKB:P0DL65"
SQ   SEQUENCE   57 AA;  6469 MW;  78DCE0B71784A712 CRC64;
     MSRLFVFILI ALFLSAIIDV MSNFKVEGAC SKPCRKYCID KGARNGKCIN GRCHCYY