KAX15_MESMA
ID KAX15_MESMA Reviewed; 57 AA.
AC Q9NII6;
DT 19-DEC-2001, integrated into UniProtKB/Swiss-Prot.
DT 01-OCT-2000, sequence version 1.
DT 25-MAY-2022, entry version 97.
DE RecName: Full=Potassium channel toxin alpha-KTx 1.5;
DE AltName: Full=BmTX1 {ECO:0000303|PubMed:9354615};
DE AltName: Full=Neurotoxin TX1 {ECO:0000312|EMBL:AAF63971.1};
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].
RX PubMed=10698710; DOI=10.1042/bj3460805;
RA Dai L., Wu J.-J., Gu Y.-H., Lan Z.-D., Ling M.-H., Chi C.-W.;
RT "Genomic organization of three novel toxins from the scorpion Buthus
RT martensi Karsch that are active on potassium channels.";
RL Biochem. J. 346:805-809(2000).
RN [2]
RP PROTEIN SEQUENCE OF 21-57, SYNTHESIS OF 21-57, FUNCTION, ACTIVITY PROFILE,
RP SUBCELLULAR LOCATION, AND PYROGLUTAMATE FORMATION AT GLN-21.
RC TISSUE=Venom;
RX PubMed=9354615; DOI=10.1021/bi971044w;
RA Romi-Lebrun R., Lebrun B., Martin-Eauclaire M.-F., Ishiguro M.,
RA Escoubas P., Wu F.Q., Hisada M., Pongs O., Nakajima T.;
RT "Purification, characterization, and synthesis of three novel toxins from
RT the Chinese scorpion Buthus martensi, which act on K+ channels.";
RL Biochemistry 36:13473-13482(1997).
RN [3]
RP STRUCTURE BY NMR OF 21-57, AND DISULFIDE BONDS.
RX PubMed=9730813; DOI=10.1021/bi9809371;
RA Blanc E., Romi-Lebrun R., Bornet O., Nakajima T., Darbon H.;
RT "Solution structure of two new toxins from the venom of the Chinese
RT scorpion Buthus martensi Karsch blockers of potassium channels.";
RL Biochemistry 37:12412-12418(1998).
RN [4]
RP X-RAY CRYSTALLOGRAPHY (1.88 ANGSTROMS) OF 21-57, FUNCTION, SYNTHESIS OF
RP 21-57, 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: Potent blocker of both large-conductance calcium-activated
CC potassium channels (KCa1.1/KCNMA1) and voltage-gated potassium channels
CC (Kv1.3/KCNA3) (PubMed:9354615, PubMed:29483648). Has also been shown to
CC moderately inhibit Kv1.2/KCNA2 and weakly inhibit Kv1.1/KCNA1 channels,
CC as well as 5-hydroxytryptamine 3 receptors (HTR3A) (PubMed:29483648).
CC {ECO:0000269|PubMed:29483648, ECO:0000269|PubMed:9354615}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:9354615}.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC {ECO:0000305|PubMed:9354615}.
CC -!- DOMAIN: Has the structural arrangement of an alpha-helix connected to a
CC beta-sheet by disulfide bonds (CSalpha/beta).
CC -!- SIMILARITY: Belongs to the short scorpion toxin superfamily. Potassium
CC channel inhibitor family. Alpha-KTx 01 subfamily. {ECO:0000305}.
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DR EMBL; AF208299; AAF63971.1; -; Genomic_DNA.
DR PDB; 1BIG; NMR; -; A=22-57.
DR PDB; 6AVC; X-ray; 1.88 A; A=21-57.
DR PDBsum; 1BIG; -.
DR PDBsum; 6AVC; -.
DR AlphaFoldDB; Q9NII6; -.
DR BMRB; Q9NII6; -.
DR SMR; Q9NII6; -.
DR EvolutionaryTrace; Q9NII6; -.
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 3D-structure; Calcium-activated potassium channel impairing toxin;
KW Direct protein sequencing; Disulfide bond; Ion channel impairing toxin;
KW Neurotoxin; Potassium channel impairing toxin; Pyrrolidone carboxylic acid;
KW Secreted; Signal; Toxin; Voltage-gated potassium channel impairing toxin.
FT SIGNAL 1..20
FT /evidence="ECO:0000269|PubMed:9354615"
FT CHAIN 21..57
FT /note="Potassium channel toxin alpha-KTx 1.5"
FT /evidence="ECO:0000269|PubMed:9354615"
FT /id="PRO_0000035317"
FT SITE 47
FT /note="Basic residue of the functional dyad"
FT /evidence="ECO:0000250"
FT SITE 56
FT /note="Aromatic residue of the functional dyad"
FT /evidence="ECO:0000250"
FT MOD_RES 21
FT /note="Pyrrolidone carboxylic acid"
FT /evidence="ECO:0000269|PubMed:9354615"
FT DISULFID 27..48
FT /evidence="ECO:0000269|PubMed:29483648,
FT ECO:0000269|PubMed:9730813, ECO:0000312|PDB:1BIG,
FT ECO:0000312|PDB:6AVC"
FT DISULFID 33..53
FT /evidence="ECO:0000269|PubMed:29483648,
FT ECO:0000269|PubMed:9730813, ECO:0000312|PDB:1BIG,
FT ECO:0000312|PDB:6AVC"
FT DISULFID 37..55
FT /evidence="ECO:0000269|PubMed:29483648,
FT ECO:0000269|PubMed:9730813, ECO:0000312|PDB:1BIG,
FT ECO:0000312|PDB:6AVC"
FT STRAND 21..26
FT /evidence="ECO:0007829|PDB:6AVC"
FT HELIX 30..32
FT /evidence="ECO:0007829|PDB:6AVC"
FT HELIX 33..41
FT /evidence="ECO:0007829|PDB:6AVC"
FT STRAND 46..49
FT /evidence="ECO:0007829|PDB:6AVC"
FT STRAND 52..55
FT /evidence="ECO:0007829|PDB:6AVC"
SQ SEQUENCE 57 AA; 6370 MW; 78C2184A587BBADB CRC64;
MKISFLLLAL VICSIGWSEA QFTDVKCTGS KQCWPVCKQM FGKPNGKCMN GKCRCYS
