KA162_MESMA
ID KA162_MESMA Reviewed; 59 AA.
AC Q9NBG9; D9IAV9; F5CJV9;
DT 19-DEC-2001, integrated into UniProtKB/Swiss-Prot.
DT 01-OCT-2000, sequence version 1.
DT 25-MAY-2022, entry version 95.
DE RecName: Full=Potassium channel toxin alpha-KTx 16.2;
DE AltName: Full=BmK 622;
DE AltName: Full=BmTx3B;
DE AltName: Full=Martentoxin;
DE Contains:
DE RecName: Full=Martentoxin-1;
DE AltName: Full=Martentoxin I;
DE Contains:
DE RecName: Full=Martentoxin-b;
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 [GENOMIC DNA / MRNA], PROTEIN SEQUENCE OF 23-59, MASS
RP SPECTROMETRY, AND FUNCTION.
RC TISSUE=Venom, and Venom gland;
RX PubMed=12558995; DOI=10.1046/j.1471-4159.2003.01516.x;
RA Ji Y.-H., Wang W.-X., Ye J.-G., He L.-L., Li Y.-J., Yan Y.-P., Zhou Z.;
RT "Martentoxin, a novel K+-channel-blocking peptide: purification, cDNA and
RT genomic cloning, and electrophysiological and pharmacological
RT characterization.";
RL J. Neurochem. 84:325-335(2003).
RN [2]
RP NUCLEOTIDE SEQUENCE [MRNA], AND SITE THR-38.
RC TISSUE=Venom gland;
RX PubMed=21466856; DOI=10.1016/j.cbpa.2011.03.027;
RA Gao B., Peigneur S., Dalziel J., Tytgat J., Zhu S.;
RT "Molecular divergence of two orthologous scorpion toxins affecting
RT potassium channels.";
RL Comp. Biochem. Physiol. 159:313-321(2011).
RN [3]
RP PROTEIN SEQUENCE OF 23-59, FUNCTION, AND MASS SPECTROMETRY.
RC TISSUE=Venom;
RX PubMed=14632928; DOI=10.1046/j.1399-3011.2003.00095.x;
RA Cao Z.Y., Shen W.Q., Pan Y.P., Xiao X., Liu X.M., Wang X.L., Liang X.T.,
RA Yu D.Q.;
RT "Purification, characterization of two peptides from Buthus martensi
RT Karch.";
RL J. Pept. Res. 62:252-259(2003).
RN [4]
RP 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 [5]
RP FUNCTION.
RX PubMed=18199674; DOI=10.1529/biophysj.107.122150;
RA Shi J., He H.Q., Zhao R., Duan Y.-H., Chen J., Chen Y., Yang J.,
RA Zhang J.W., Shu X.Q., Zheng P., Ji Y.H.;
RT "Inhibition of martentoxin on neuronal BK channel subtype (alpha+beta4):
RT implications for a novel interaction model.";
RL Biophys. J. 94:3706-3713(2008).
RN [6]
RP STRUCTURE BY NMR OF 23-59, AND DISULFIDE BONDS.
RX PubMed=15558557; DOI=10.1002/prot.20322;
RA Wang Y., Chen X., Zhang N., Wu G., Wu H.;
RT "The solution structure of BmTx3B, a member of the scorpion toxin subfamily
RT alpha-KTx 16.";
RL Proteins 58:489-497(2005).
CC -!- FUNCTION: Alpha-KTx 16.2: inhibits large conductance calcium-activated
CC potassium channels (KCa1.1/Slo-beta4 KCNMA1/KCNMB4). It appears to
CC block channel activity by a simple bimolecular inhibition process.
CC Shows a fast association rate and a slow dissociation rate of binding
CC on rat brain synaptosome (PubMed:18199674). Significantly inhibits
CC voltage-dependent sodium current and voltage-dependent delayed
CC rectifier potassium currents (PubMed:14632928).
CC {ECO:0000269|PubMed:14632928, ECO:0000269|PubMed:18199674}.
CC -!- FUNCTION: [Martentoxin-1]: Significantly inhibits voltage-dependent
CC sodium current (Nav) and voltage-dependent delayed rectifier potassium
CC current. {ECO:0000269|PubMed:14632928}.
CC -!- SUBCELLULAR LOCATION: Secreted.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC -!- DOMAIN: Has the structural arrangement of an alpha-helix connected to a
CC beta-sheet by disulfide bonds (CSalpha/beta).
CC {ECO:0000269|PubMed:15558557}.
CC -!- MASS SPECTROMETRY: [Potassium channel toxin alpha-KTx 16.2]: Mass=4060;
CC Method=Electrospray; Evidence={ECO:0000269|PubMed:12558995};
CC -!- MASS SPECTROMETRY: [Potassium channel toxin alpha-KTx 16.2]:
CC Mass=4056.3; Method=MALDI; Evidence={ECO:0000269|PubMed:14632928};
CC -!- MASS SPECTROMETRY: [Martentoxin-b]: Mass=3852.89; Method=Electrospray;
CC Note=Monoisotopic mass.; Evidence={ECO:0000269|PubMed:22887697};
CC -!- MASS SPECTROMETRY: [Martentoxin-1]: Mass=3908.0; Method=MALDI;
CC Evidence={ECO:0000269|PubMed:14632928};
CC -!- SIMILARITY: Belongs to the short scorpion toxin superfamily. Potassium
CC channel inhibitor family. Alpha-KTx 16 subfamily. {ECO:0000305}.
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DR EMBL; AF249746; AAF87224.1; -; mRNA.
DR EMBL; AF534113; AAM97931.1; -; Genomic_DNA.
DR EMBL; JF719810; AEC22866.1; -; mRNA.
DR EMBL; HM131808; ADJ17366.1; -; mRNA.
DR EMBL; HM197724; ADK13081.1; -; mRNA.
DR EMBL; HM197725; ADK13082.1; -; mRNA.
DR EMBL; HM197726; ADK13083.1; -; mRNA.
DR EMBL; HM197727; ADK13084.1; -; mRNA.
DR EMBL; HM197728; ADK13085.1; -; mRNA.
DR EMBL; HM197729; ADK13086.1; -; mRNA.
DR EMBL; HM197730; ADK13087.1; -; mRNA.
DR PDB; 1M2S; NMR; -; A=23-59.
DR PDBsum; 1M2S; -.
DR AlphaFoldDB; Q9NBG9; -.
DR SMR; Q9NBG9; -.
DR TCDB; 8.B.8.1.5; the Alpha-ktx15 scorpion toxin (Alpha-ktx15) family.
DR EvolutionaryTrace; Q9NBG9; -.
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:0017080; F:sodium 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 1: Evidence at protein level;
KW 3D-structure; Calcium-activated potassium channel impairing toxin;
KW Direct protein sequencing; Disulfide bond; Ion channel impairing toxin;
KW Neurotoxin; Potassium channel impairing toxin; Secreted; Signal; Toxin;
KW Voltage-gated sodium channel impairing toxin.
FT SIGNAL 1..22
FT /evidence="ECO:0000269|PubMed:12558995,
FT ECO:0000269|PubMed:14632928"
FT PEPTIDE 23..59
FT /note="Potassium channel toxin alpha-KTx 16.2"
FT /id="PRO_0000035321"
FT PEPTIDE 24..59
FT /note="Martentoxin-1"
FT /id="PRO_0000035322"
FT PEPTIDE 25..59
FT /note="Martentoxin-b"
FT /id="PRO_0000431603"
FT SITE 38
FT /note="Important for the inhibitory effect on KCNMA1
FT channels"
FT SITE 50
FT /note="Basic residue of the functional dyad"
FT /evidence="ECO:0000250"
FT SITE 59
FT /note="Aromatic residue of the functional dyad"
FT /evidence="ECO:0000250"
FT DISULFID 30..51
FT /evidence="ECO:0000269|PubMed:15558557"
FT DISULFID 36..56
FT /evidence="ECO:0000269|PubMed:15558557"
FT DISULFID 40..58
FT /evidence="ECO:0000269|PubMed:15558557"
FT HELIX 33..43
FT /evidence="ECO:0007829|PDB:1M2S"
FT STRAND 49..52
FT /evidence="ECO:0007829|PDB:1M2S"
FT STRAND 55..58
FT /evidence="ECO:0007829|PDB:1M2S"
SQ SEQUENCE 59 AA; 6429 MW; A1A1A2C415D456A7 CRC64;
MKIFSILLVA LIICSISICT EAFGLIDVKC FASSECWTAC KKVTGSGQGK CQNNQCRCY
