ID   KAX3I_MESEU             Reviewed;          61 AA.
AC   C0HJQ4; A0A088DB20;
DT   27-MAY-2015, integrated into UniProtKB/Swiss-Prot.
DT   27-MAY-2015, sequence version 1.
DT   25-MAY-2022, entry version 14.
DE   RecName: Full=Potassium channel toxin alpha-KTx 3.18 {ECO:0000305};
DE   AltName: Full=Toxin MeKTx13-2 {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 24-60, MASS SPECTROMETRY,
RP   SUBCELLULAR LOCATION, AND AMIDATION AT LYS-60.
RC   TISSUE=Venom, and Venom gland;
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).
CC   -!- FUNCTION: Inhibits voltage-gated potassium channel rKv1.1/KCNA1 at
CC       nanomolar ranges (IC(50)=90 +-2 nM, reduction of current by 30% at 50
CC       nM or toxin). {ECO:0000269|PubMed:25792741}.
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=4047; Method=MALDI;
CC       Evidence={ECO:0000269|PubMed:25792741};
CC   -!- SIMILARITY: Belongs to the short scorpion toxin superfamily. Potassium
CC       channel inhibitor family. Alpha-KTx 03 subfamily.
CC       {ECO:0000303|PubMed:25792741}.
CC   ---------------------------------------------------------------------------
CC   Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC   Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC   ---------------------------------------------------------------------------
DR   EMBL; KF612526; AIL48784.1; -; mRNA.
DR   AlphaFoldDB; C0HJQ4; -.
DR   SMR; C0HJQ4; -.
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.
DR   PROSITE; PS01138; SCORP_SHORT_TOXIN; 1.
PE   1: Evidence at protein level;
KW   Amidation; Direct protein sequencing; Disulfide bond;
KW   Ion channel impairing toxin; Potassium channel impairing toxin; Secreted;
KW   Signal; Toxin; Voltage-gated potassium channel impairing toxin.
FT   SIGNAL          1..23
FT                   /evidence="ECO:0000269|PubMed:25792741"
FT   CHAIN           24..60
FT                   /note="Potassium channel toxin alpha-KTx 3.18"
FT                   /evidence="ECO:0000269|PubMed:25792741"
FT                   /id="PRO_0000433141"
FT   MOD_RES         60
FT                   /note="Lysine amide"
FT                   /evidence="ECO:0000269|PubMed:25792741"
FT   DISULFID        30..50
FT                   /evidence="ECO:0000250|UniProtKB:P55896"
FT   DISULFID        36..55
FT                   /evidence="ECO:0000250|UniProtKB:P55896"
FT   DISULFID        40..57
FT                   /evidence="ECO:0000250|UniProtKB:P55896"
SQ   SEQUENCE   61 AA;  6676 MW;  88480E2564F89810 CRC64;
     MKMFFTVLVT LFVCSMIIGI CEGREIPVKC KGSKQCLQSC KEAGMTYGKC MNGKCNCTPK
     G