ID   KAX1G_MESEU             Reviewed;          58 AA.
AC   C0HJQ8; A0A088D9T2;
DT   27-MAY-2015, integrated into UniProtKB/Swiss-Prot.
DT   27-MAY-2015, sequence version 1.
DT   25-MAY-2022, entry version 16.
DE   RecName: Full=Potassium channel toxin alpha-KTx 1.16 {ECO:0000305|PubMed:25792741};
DE   AltName: Full=Toxin MeKTx11-1 {ECO:0000303|PubMed:25792741};
DE   Flags: Precursor;
OS   Mesobuthus eupeus (Lesser Asian scorpion) (Buthus eupeus).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Mesobuthus.
OX   NCBI_TaxID=34648;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], PROTEIN SEQUENCE OF 22-58, PYROGLUTAMATE
RP   FORMATION AT GLN-22, SUBCELLULAR LOCATION, AND MASS SPECTROMETRY.
RC   TISSUE=Venom;
RX   PubMed=25792741; DOI=10.1074/jbc.m115.637611;
RA   Kuzmenkov A.I., Vassilevski A.A., Kudryashova K.S., Nekrasova O.V.,
RA   Peigneur S., Tytgat J., Feofanov A.V., Kirpichnikov M.P., Grishin E.V.;
RT   "Variability of potassium channel blockers in Mesobuthus eupeus scorpion
RT   venom with focus on Kv1.1: an integrated transcriptomic and proteomic
RT   study.";
RL   J. Biol. Chem. 290:12195-12209(2015).
RN   [2]
RP   FUNCTION, 3D-STRUCTURE MODELING ALONE; IN COMPLEX WITH KV1.2 AND IN COMPLEX
RP   WITH KV1.3, AND MUTAGENESIS OF GLY-30 AND PRO-58.
RC   TISSUE=Venom;
RX   PubMed=30248306; DOI=10.1016/j.neuropharm.2018.09.030;
RA   Kuzmenkov A.I., Nekrasova O.V., Peigneur S., Tabakmakher V.M.,
RA   Gigolaev A.M., Fradkov A.F., Kudryashova K.S., Chugunov A.O., Efremov R.G.,
RA   Tytgat J., Feofanov A.V., Vassilevski A.A.;
RT   "KV1.2 channel-specific blocker from Mesobuthus eupeus scorpion venom:
RT   Structural basis of selectivity.";
RL   Neuropharmacology 143:228-238(2018).
CC   -!- FUNCTION: Inhibits voltage-gated potassium channel rKv1.1/KCNA1
CC       (IC(50)=780-2110 nM), rKv1.2/KCNA2 (IC(50)=0.19 nM), hKv1.3/KCNA3
CC       (IC(50)=67 nM), and rKv1.6/KCNA6 (IC(50)=8.9 uM) (PubMed:25792741,
CC       PubMed:30248306). Its activity (tested on Kv1.2) is not voltage-
CC       dependent (PubMed:30248306). {ECO:0000269|PubMed:25792741,
CC       ECO:0000269|PubMed:30248306}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:25792741}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000305|PubMed:25792741}.
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=4222; Method=MALDI;
CC       Evidence={ECO:0000269|PubMed:25792741};
CC   -!- MISCELLANEOUS: Does not inhibit Kv1.4/KCNA4, Kv1.5/KCNA5, Kv2.1/KCNB1,
CC       Kv3.1/KCNC1, Kv4.2/KCND2, Kv11.1/KCNH2, Nav1.1/SCN1A, Nav1.2/SCN2A,
CC       Nav1.4/SCN4A, Nav1.5/SCN5A, B.germanica Nav1, and Cav3.3/CACNA1I (when
CC       1 uM is tested). {ECO:0000269|PubMed:30248306}.
CC   -!- SIMILARITY: Belongs to the short scorpion toxin superfamily. Potassium
CC       channel inhibitor family. Alpha-KTx 01 subfamily.
CC       {ECO:0000303|PubMed:25792741}.
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DR   EMBL; KF612509; AIL48767.1; -; mRNA.
DR   AlphaFoldDB; C0HJQ8; -.
DR   SMR; C0HJQ8; -.
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.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Disulfide bond; Ion channel impairing toxin;
KW   Potassium channel impairing toxin; Pyrrolidone carboxylic acid; Secreted;
KW   Signal; Toxin; Voltage-gated potassium channel impairing toxin.
FT   SIGNAL          1..21
FT                   /evidence="ECO:0000269|PubMed:25792741"
FT   CHAIN           22..58
FT                   /note="Potassium channel toxin alpha-KTx 1.16"
FT                   /evidence="ECO:0000269|PubMed:25792741"
FT                   /id="PRO_0000433137"
FT   SITE            48
FT                   /note="Basic residue of the functional dyad"
FT                   /evidence="ECO:0000250"
FT   SITE            57
FT                   /note="Aromatic residue of the functional dyad"
FT                   /evidence="ECO:0000250"
FT   MOD_RES         22
FT                   /note="Pyrrolidone carboxylic acid"
FT                   /evidence="ECO:0000269|PubMed:25792741"
FT   DISULFID        28..49
FT                   /evidence="ECO:0000250|UniProtKB:Q9NII6"
FT   DISULFID        34..54
FT                   /evidence="ECO:0000250|UniProtKB:Q9NII6"
FT   DISULFID        38..56
FT                   /evidence="ECO:0000250|UniProtKB:Q9NII6"
FT   MUTAGEN         30
FT                   /note="G->V: Increase in inhibition potency for Kv1.1/KCNA1
FT                   (1.5-fold), Kv1.2/KCNA2 (2.7-fold), Kv1.3/KCNA3 (50-fold),
FT                   and Kv1.6/KCNA6 (1.3-fold)."
FT                   /evidence="ECO:0000269|PubMed:30248306"
FT   MUTAGEN         58
FT                   /note="P->S: Increase in inhibition potency for Kv1.1/KCNA1
FT                   (2.8-fold), Kv1.2/KCNA2 (2.1-fold), Kv1.3/KCNA3 (5-fold),
FT                   and Kv1.6/KCNA6 (1.5-fold)."
FT                   /evidence="ECO:0000269|PubMed:30248306"
SQ   SEQUENCE   58 AA;  6535 MW;  41565D930EE06988 CRC64;
     MKISFLLLLA LVICSIGWSE AQFTDVKCTG TKQCWPVCKK MFGRPNGKCM NGKCRCYP