KAX1H_MESEU
ID KAX1H_MESEU Reviewed; 37 AA.
AC C0HJQ7;
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 1.17 {ECO:0000305|PubMed:25792741};
DE AltName: Full=Toxin MeKTx11-3 {ECO:0000303|PubMed:25792741};
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 PROTEIN SEQUENCE, PYROGLUTAMATE FORMATION AT GLN-1, FUNCTION, MASS
RP SPECTROMETRY, AND SUBCELLULAR LOCATION.
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, AND 3D-STRUCTURE MODELING ALONE; IN COMPLEX WITH KV1.2 AND IN
RP COMPLEX WITH KV1.3.
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)=130-135 nM), rKv1.2/KCNA2 (IC(50)=3.1 nM), hKv1.3/KCNA3
CC (IC(50)=78 nM), and rKv1.6/KCNA6 (IC(50)=910 nM) (PubMed:25792741,
CC PubMed:30248306). Its activity (tested on Kv1.2) is not voltage-
CC dependent (By similarity). {ECO:0000250|UniProtKB:C0HJQ8,
CC ECO:0000269|PubMed:25792741, 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=4255; 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 AlphaFoldDB; C0HJQ7; -.
DR SMR; C0HJQ7; -.
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 Toxin; Voltage-gated potassium channel impairing toxin.
FT CHAIN 1..37
FT /note="Potassium channel toxin alpha-KTx 1.17"
FT /evidence="ECO:0000269|PubMed:25792741"
FT /id="PRO_0000433138"
FT SITE 27
FT /note="Basic residue of the functional dyad"
FT /evidence="ECO:0000250"
FT SITE 36
FT /note="Aromatic residue of the functional dyad"
FT /evidence="ECO:0000250"
FT MOD_RES 1
FT /note="Pyrrolidone carboxylic acid"
FT /evidence="ECO:0000269|PubMed:25792741"
FT DISULFID 7..28
FT /evidence="ECO:0000250|UniProtKB:Q9NII6"
FT DISULFID 13..33
FT /evidence="ECO:0000250|UniProtKB:Q9NII6"
FT DISULFID 17..35
FT /evidence="ECO:0000250|UniProtKB:Q9NII6"
SQ SEQUENCE 37 AA; 4277 MW; 75C95F02CA01AD43 CRC64;
QFTDVKCTVT KQCWPVCKKM FGRPNGKCMN GKCRCYS