KGX22_MESMA
ID KGX22_MESMA Reviewed; 57 AA.
AC P59938;
DT 31-OCT-2003, integrated into UniProtKB/Swiss-Prot.
DT 31-OCT-2003, sequence version 1.
DT 25-MAY-2022, entry version 67.
DE RecName: Full=Potassium channel toxin gamma-KTx 2.2;
DE AltName: Full=BmKK7 {ECO:0000303|PubMed:22887697};
DE AltName: Full=BmKKx2 {ECO:0000303|PubMed:16513212};
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=16513212; DOI=10.1016/j.peptides.2006.01.012;
RA Zeng X.-C., Luo F., Li W.-X.;
RT "Molecular dissection of venom from Chinese scorpion Mesobuthus martensii:
RT identification and characterization of four novel disulfide-bridged venom
RT peptides.";
RL Peptides 27:1745-1754(2006).
RN [2]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=23573241; DOI=10.1371/journal.pone.0060201;
RA Chen Z., Luo F., Feng J., Yang W., Zeng D., Zhao R., Cao Z., Liu M., Li W.,
RA Jiang L., Wu Y.;
RT "Genomic and structural characterization of Kunitz-type peptide LmKTT-1a
RT highlights diversity and evolution of scorpion potassium channel toxins.";
RL PLoS ONE 8:E60201-E60201(2013).
RN [3]
RP PROTEIN SEQUENCE OF 22-27, 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).
RN [4]
RP X-RAY CRYSTALLOGRAPHY (1.90 ANGSTROMS) OF 22-57, FUNCTION, SYNTHESIS OF
RP 22-57, AND DISULFIDE BONDS.
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: Blocks human and/or rat Kv11.1/KCNH2/ERG1, Kv11.2/KCNH6/ERG2
CC and Kv11.3/KCNH7/ERG3 by binding to channel outer vestibule (S5P
CC domain) with a 1:1 stoichiometry (By similarity). Has also a minimal
CC effect on rat ELK1/KCNH4 potassium channels (By similarity). Has been
CC shown to weakly inhibit Kv11.1/KCNH2/ERG1, Kv1.1/KCNA1, Kv1.2/KCNA2 and
CC Kv1.3/KCNA3 voltage-gated potassium channels (PubMed:29483648).
CC {ECO:0000250|UniProtKB:Q9BKB7, ECO:0000269|PubMed:29483648}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:22887697}.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC {ECO:0000305|PubMed:22887697}.
CC -!- DOMAIN: Has the CSalpha/beta fold, which comprises one or two short
CC alpha helices connected to anti-parallel beta-sheets stabilized by
CC three or four disulfide bonds. {ECO:0000250|UniProtKB:Q9BKB7}.
CC -!- MASS SPECTROMETRY: Mass=3997.66; 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. Gamma-KTx 2 subfamily. {ECO:0000305}.
CC -!- CAUTION: Has been classified as a gamma-KTx toxin due to its molecular
CC target (Kv11/ERG), but could be classified as an alpha-KTx since it
CC shares a high level of homology in both primary and 3D structures with
CC other alpha-KTx scorpion toxins. {ECO:0000305}.
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DR EMBL; AF154634; AAP43907.1; -; mRNA.
DR PDB; 6AU7; X-ray; 1.90 A; A/B/C/D=22-57.
DR PDB; 6AUP; X-ray; 1.95 A; A/B/C/D/E/F/G/H/I/J/K/L/M/N/O/P=22-57.
DR PDBsum; 6AU7; -.
DR PDBsum; 6AUP; -.
DR AlphaFoldDB; P59938; -.
DR SMR; P59938; -.
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.
PE 1: Evidence at protein level;
KW 3D-structure; Direct protein sequencing; Disulfide bond;
KW Ion channel impairing toxin; Neurotoxin; Potassium channel impairing toxin;
KW Secreted; Signal; Toxin; Voltage-gated potassium channel impairing toxin.
FT SIGNAL 1..21
FT /evidence="ECO:0000269|PubMed:22887697"
FT CHAIN 22..57
FT /note="Potassium channel toxin gamma-KTx 2.2"
FT /id="PRO_0000066831"
FT DISULFID 28..49
FT /evidence="ECO:0000269|PubMed:29483648,
FT ECO:0000312|PDB:6AU7, ECO:0000312|PDB:6AUP"
FT DISULFID 34..54
FT /evidence="ECO:0000269|PubMed:29483648,
FT ECO:0000312|PDB:6AU7, ECO:0000312|PDB:6AUP"
FT DISULFID 38..56
FT /evidence="ECO:0000269|PubMed:29483648,
FT ECO:0000312|PDB:6AU7, ECO:0000312|PDB:6AUP"
FT STRAND 22..27
FT /evidence="ECO:0007829|PDB:6AU7"
FT HELIX 31..33
FT /evidence="ECO:0007829|PDB:6AU7"
FT HELIX 34..42
FT /evidence="ECO:0007829|PDB:6AU7"
FT STRAND 45..50
FT /evidence="ECO:0007829|PDB:6AU7"
FT STRAND 53..57
FT /evidence="ECO:0007829|PDB:6AU7"
SQ SEQUENCE 57 AA; 6360 MW; 8B85BF822E256666 CRC64;
MKISFVLLLT LFICSIGWSE ARPTDIKCSA SYQCFPVCKS RFGKTNGRCV NGLCDCF
