ID   KA191_MESMA             Reviewed;          31 AA.
AC   P83407;
DT   01-NOV-2002, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-2002, sequence version 1.
DT   25-MAY-2022, entry version 78.
DE   RecName: Full=Potassium channel toxin alpha-KTx 19.1;
DE   AltName: Full=BmK37;
DE   AltName: Full=Neurotoxin BmBKTx1;
OS   Mesobuthus martensii (Manchurian scorpion) (Buthus martensii).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida;
OC   Scorpiones; Buthida; Buthoidea; Buthidae; Mesobuthus.
OX   NCBI_TaxID=34649 {ECO:0000305};
RN   [1] {ECO:0000305}
RP   PROTEIN SEQUENCE, FUNCTION, SUBUNIT, SUBCELLULAR LOCATION, TISSUE
RP   SPECIFICITY, MASS SPECTROMETRY, AND DISULFIDE BONDS.
RC   TISSUE=Venom;
RA   Xu C.-Q., Chi C.-W.;
RL   Submitted (JUL-2002) to UniProtKB.
RN   [2]
RP   PROTEIN SEQUENCE, SYNTHESIS, AND FUNCTION.
RC   TISSUE=Venom;
RX   PubMed=15178692; DOI=10.1074/jbc.m312798200;
RA   Xu C.-Q., Brone B., Wicher D., Bozkurt O., Lu W.-Y., Huys I., Han Y.-H.,
RA   Tytgat J., Van Kerkhove E., Chi C.-W.;
RT   "BmBKTx1, a novel Ca2+-activated K+ channel blocker purified from the Asian
RT   scorpion Buthus martensi Karsch.";
RL   J. Biol. Chem. 279:34562-34569(2004).
RN   [3]
RP   STRUCTURE BY NMR, AND DISULFIDE BONDS.
RX   PubMed=15049683; DOI=10.1021/bi035412+;
RA   Cai Z., Xu C.-Q., Xu Y., Lu W., Chi C.-W., Shi Y., Wu J.;
RT   "Solution structure of BmBKTx1, a new BKCa1 channel blocker from the
RT   Chinese scorpion Buthus martensi Karsch.";
RL   Biochemistry 43:3764-3771(2004).
RN   [4]
RP   X-RAY CRYSTALLOGRAPHY (1.72 ANGSTROMS) OF 2-30.
RX   PubMed=14960379; DOI=10.1016/j.jsb.2003.11.012;
RA   Szyk A., Lu W.-Y., Xu C.-Q., Lubkowski J.;
RT   "Structure of the scorpion toxin BmBKTtx1 solved from single wavelength
RT   anomalous scattering of sulfur.";
RL   J. Struct. Biol. 145:289-294(2004).
CC   -!- FUNCTION: Selective inhibitor of high conductance calcium-activated
CC       potassium channels KCa1.1/KCNMA1. May be insect specific.
CC       {ECO:0000269|PubMed:15178692, ECO:0000269|Ref.1}.
CC   -!- SUBUNIT: Monomer. {ECO:0000269|Ref.1, ECO:0000305}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|Ref.1, ECO:0000305}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000269|Ref.1}.
CC   -!- DOMAIN: Has the structural arrangement of an alpha-helix connected to a
CC       beta-sheet by disulfide bonds (CSalpha/beta).
CC   -!- MASS SPECTROMETRY: Mass=3335.14; Method=MALDI;
CC       Evidence={ECO:0000269|Ref.1};
CC   -!- MISCELLANEOUS: Has no effect on voltage-gated potassium channels
CC       Kv1.1/KCNA1, Kv1.2/KCNA2, Kv1.3/KCNA3, Kv11.1/KCNH2, Kv11.2/KCNH6,
CC       Kv11.3/KCNH7, Kv7.1/KCNQ1 and on Kir2.1/KCNJ2.
CC       {ECO:0000305|PubMed:15178692}.
CC   -!- SIMILARITY: Belongs to the short scorpion toxin superfamily. Potassium
CC       channel inhibitor family. Alpha-KTx 19 subfamily. {ECO:0000305}.
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DR   PDB; 1Q2K; NMR; -; A=1-31.
DR   PDB; 1R1G; X-ray; 1.72 A; A/B=1-31.
DR   PDB; 3E8Y; X-ray; 1.10 A; X=1-31.
DR   PDBsum; 1Q2K; -.
DR   PDBsum; 1R1G; -.
DR   PDBsum; 3E8Y; -.
DR   AlphaFoldDB; P83407; -.
DR   SMR; P83407; -.
DR   EvolutionaryTrace; P83407; -.
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.
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; Toxin.
FT   PEPTIDE         1..31
FT                   /note="Potassium channel toxin alpha-KTx 19.1"
FT                   /id="PRO_0000044898"
FT   SITE            9
FT                   /note="Crucial for toxin binding"
FT                   /evidence="ECO:0000305"
FT   SITE            11
FT                   /note="Crucial for toxin binding"
FT                   /evidence="ECO:0000305"
FT   SITE            21
FT                   /note="Basic residue of the functional dyad"
FT                   /evidence="ECO:0000250"
FT   SITE            30
FT                   /note="Aromatic residue of the functional dyad"
FT                   /evidence="ECO:0000250"
FT   DISULFID        3..22
FT                   /evidence="ECO:0000305"
FT   DISULFID        8..27
FT                   /evidence="ECO:0000305"
FT   DISULFID        12..29
FT                   /evidence="ECO:0000305"
FT   HELIX           5..14
FT                   /evidence="ECO:0007829|PDB:3E8Y"
FT   STRAND          18..23
FT                   /evidence="ECO:0007829|PDB:3E8Y"
FT   STRAND          26..30
FT                   /evidence="ECO:0007829|PDB:3E8Y"
SQ   SEQUENCE   31 AA;  3342 MW;  FD13B6FDB90746F1 CRC64;
     AACYSSDCRV KCVAMGFSSG KCINSKCKCY K