K1B_BUNGR
ID K1B_BUNGR Reviewed; 37 AA.
AC P29186;
DT 01-DEC-1992, integrated into UniProtKB/Swiss-Prot.
DT 01-NOV-1997, sequence version 2.
DT 25-MAY-2022, entry version 99.
DE RecName: Full=Kappa-actitoxin-Bgr1a {ECO:0000303|PubMed:22683676};
DE Short=Kappa-AITX-Bgr1a {ECO:0000303|PubMed:22683676};
DE AltName: Full=Potassium channel toxin Bgk {ECO:0000303|PubMed:11707459, ECO:0000303|PubMed:8098956};
OS Bunodosoma granuliferum (Red warty sea anemone).
OC Eukaryota; Metazoa; Cnidaria; Anthozoa; Hexacorallia; Actiniaria;
OC Actiniidae; Bunodosoma.
OX NCBI_TaxID=31164;
RN [1]
RP PROTEIN SEQUENCE, FUNCTION, AND MASS SPECTROMETRY.
RC TISSUE=Nematoblast;
RX PubMed=8098956; DOI=10.1016/0304-4165(93)90082-j;
RA Aneiros A., Garcia I., Martinez J.R., Harvey A.L., Anderson A.J.,
RA Marshall D.L., Engstroem A., Hellman U., Karlsson E.;
RT "A potassium channel toxin from the secretion of the sea anemone Bunodosoma
RT granulifera. Isolation, amino acid sequence and biological activity.";
RL Biochim. Biophys. Acta 1157:86-92(1993).
RN [2]
RP PROTEIN SEQUENCE, SEQUENCE REVISION TO 34-36, DISULFIDE BONDS, FUNCTION,
RP AND TOXIC DOSE.
RX PubMed=9063464; DOI=10.1111/j.1432-1033.1997.00192.x;
RA Cotton J., Crest M., Bouet F., Alessandri N., Gola M., Forest E.,
RA Karlsson E., Castaneda O., Harvey A.L., Vita C., Menez A.;
RT "A potassium-channel toxin from the sea anemone Bunodosoma granulifera, an
RT inhibitor for Kv1 channels. Revision of the amino acid sequence, disulfide-
RT bridge assignment, chemical synthesis, and biological activity.";
RL Eur. J. Biochem. 244:192-202(1997).
RN [3]
RP FUNCTION.
RX PubMed=10419508; DOI=10.1074/jbc.274.31.21885;
RA Rauer H., Pennington M., Cahalan M., Chandy K.G.;
RT "Structural conservation of the pores of calcium-activated and voltage-
RT gated potassium channels determined by a sea anemone toxin.";
RL J. Biol. Chem. 274:21885-21892(1999).
RN [4]
RP FUNCTION, AND MUTAGENESIS OF VAL-1; ARG-3; ASP-4; TRP-5; PHE-6; LYS-7;
RP GLU-8; THR-9; ARG-12; HIS-13; LYS-15; SER-16; LEU-17; ASN-19; ARG-21;
RP THR-22; SER-23; GLN-24; LYS-25; TYR-26; ARG-27; ASN-29; LYS-32; THR-33;
RP GLU-35 AND LEU-36.
RX PubMed=10585444; DOI=10.1074/jbc.274.50.35653;
RA Alessandri-Haber N., Lecoq A., Gasparini S., Grangier-Macmath G.,
RA Jacquet G., Harvey A.L., de Medeiros C., Rowan E.G., Gola M., Menez A.,
RA Crest M.;
RT "Mapping the functional anatomy of BgK on Kv1.1, Kv1.2, and Kv1.3. Clues to
RT design analogs with enhanced selectivity.";
RL J. Biol. Chem. 274:35653-35661(1999).
RN [5]
RP FUNCTION, AND MUTAGENESIS OF TRP-5; PHE-6 AND TYR-26.
RX PubMed=11707459; DOI=10.1074/jbc.m109886200;
RA Racape J., Lecoq A., Romi-Lebrun R., Liu J., Kohler M., Garcia M.L.,
RA Menez A., Gasparini S.;
RT "Characterization of a novel radiolabeled peptide selective for a
RT subpopulation of voltage-gated potassium channels in mammalian brain.";
RL J. Biol. Chem. 277:3886-3893(2002).
RN [6]
RP MASS SPECTROMETRY.
RX PubMed=22015268; DOI=10.1016/j.peptides.2011.10.011;
RA Rodriguez A.A., Cassoli J.S., Sa F., Dong Z.Q., de Freitas J.C.,
RA Pimenta A.M., de Lima M.E., Konno K., Lee S.M., Garateix A.,
RA Zaharenko A.J.;
RT "Peptide fingerprinting of the neurotoxic fractions isolated from the
RT secretions of sea anemones Stichodactyla helianthus and Bunodosoma
RT granulifera. New members of the APETx-like family identified by a 454
RT pyrosequencing approach.";
RL Peptides 34:26-38(2012).
RN [7]
RP NOMENCLATURE.
RX PubMed=22683676; DOI=10.1016/j.toxicon.2012.05.020;
RA Oliveira J.S., Fuentes-Silva D., King G.F.;
RT "Development of a rational nomenclature for naming peptide and protein
RT toxins from sea anemones.";
RL Toxicon 60:539-550(2012).
RN [8]
RP STRUCTURE BY NMR, DISULFIDE BONDS, AND MUTAGENESIS OF PHE-6; HIS-13;
RP SER-23; LYS-25 AND TYR-26.
RX PubMed=9020148; DOI=10.1074/jbc.272.7.4302;
RA Dauplais M., Lecoq A., Song J., Cotton J., Jamin N., Gilquin B.,
RA Roumestand C., Vita C., de Medeiros C.L.C., Rowan E.G., Harvey A.L.,
RA Menez A.;
RT "On the convergent evolution of animal toxins. Conservation of a diad of
RT functional residues in potassium channel-blocking toxins with unrelated
RT structures.";
RL J. Biol. Chem. 272:4302-4309(1997).
CC -!- FUNCTION: Inhibits voltage-dependent potassium channels of the Kv1
CC family (Kv1.1/KCNA1 (Kd=6 nM), Kv1.2/KCNA2 (Kd=15 nM), Kv1.3/KCNA3
CC (Kd=10-39 nM), Kv1.6/KCNA6, and KCa3.1/KCNN4 (Kd=172 nM)).
CC {ECO:0000269|PubMed:10419508, ECO:0000269|PubMed:10585444,
CC ECO:0000269|PubMed:11707459, ECO:0000269|PubMed:8098956}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000250|UniProtKB:C0HJC2}.
CC Nematocyst {ECO:0000250|UniProtKB:C0HJC2}.
CC -!- MASS SPECTROMETRY: Mass=4276.8; Method=MALDI;
CC Evidence={ECO:0000269|PubMed:22015268};
CC -!- MASS SPECTROMETRY: Mass=4272.4; Method=Plasma desorption;
CC Note=Monoisotopic mass.; Evidence={ECO:0000269|PubMed:8098956};
CC -!- TOXIC DOSE: LD(50) is 4.5 ug/kg by intracerebroventricular injection
CC into mice. Symptoms observed are trembling of tail, fasciculations,
CC salivation, paralysis and death. {ECO:0000269|PubMed:9063464}.
CC -!- MISCELLANEOUS: Does not act on Kv3.1 up to 125 nM of the toxin
CC (PubMed:9063464). Does not show effect on crabs.
CC {ECO:0000269|PubMed:22015268}.
CC -!- SIMILARITY: Belongs to the sea anemone type 1 potassium channel toxin
CC family. Type 1b subfamily. {ECO:0000305}.
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DR PIR; S33268; S33268.
DR PDB; 1BGK; NMR; -; A=1-37.
DR PDBsum; 1BGK; -.
DR AlphaFoldDB; P29186; -.
DR SMR; P29186; -.
DR TCDB; 8.B.14.1.1; the sea anemone peptide toxin, class 1 (bgk) family.
DR EvolutionaryTrace; P29186; -.
DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR GO; GO:0042151; C:nematocyst; IEA:UniProtKB-SubCell.
DR GO; GO:0015459; F:potassium channel regulator activity; IEA:UniProtKB-KW.
DR GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR InterPro; IPR003582; ShKT_dom.
DR Pfam; PF01549; ShK; 1.
DR PROSITE; PS51670; SHKT; 1.
PE 1: Evidence at protein level;
KW 3D-structure; Direct protein sequencing; Disulfide bond;
KW Ion channel impairing toxin; Nematocyst; Neurotoxin;
KW Potassium channel impairing toxin; Secreted; Toxin;
KW Voltage-gated potassium channel impairing toxin.
FT PEPTIDE 1..37
FT /note="Kappa-actitoxin-Bgr1a"
FT /evidence="ECO:0000269|PubMed:8098956"
FT /id="PRO_0000044864"
FT DOMAIN 2..37
FT /note="ShKT"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU01005"
FT REGION 25..26
FT /note="Crucial for binding to potassium channels"
FT /evidence="ECO:0000269|PubMed:10585444,
FT ECO:0000269|PubMed:9020148"
FT SITE 6
FT /note="Key residue for binding Kv1.2 and Kv1.3"
FT /evidence="ECO:0000305|PubMed:10585444,
FT ECO:0000305|PubMed:9020148"
FT SITE 7
FT /note="Key residue for binding Kv1.3"
FT /evidence="ECO:0000305|PubMed:10585444"
FT SITE 12
FT /note="Important for binding Kv1.2"
FT /evidence="ECO:0000305|PubMed:10585444"
FT SITE 13
FT /note="Important for binding Kv1.2 and Kv1.3"
FT /evidence="ECO:0000305|PubMed:10585444,
FT ECO:0000305|PubMed:9020148"
FT SITE 17
FT /note="Important for binding Kv1.3"
FT /evidence="ECO:0000305|PubMed:10585444"
FT SITE 19
FT /note="Key residue for binding Kv1.1 and Kv1.3"
FT /evidence="ECO:0000305|PubMed:10585444"
FT SITE 22
FT /note="Important for binding Kv1.3"
FT /evidence="ECO:0000305|PubMed:10585444"
FT SITE 23
FT /note="Key residue for binding Kv1.1, Kv1.2 and Kv1.3"
FT /evidence="ECO:0000305|PubMed:10585444,
FT ECO:0000305|PubMed:9020148"
FT SITE 24
FT /note="Important for binding Kv1.1 and key residue for
FT binding Kv1.3"
FT /evidence="ECO:0000305|PubMed:10585444"
FT SITE 25
FT /note="Key residue for binding Kv1.1, Kv1.2 and Kv1.3"
FT /evidence="ECO:0000305|PubMed:10585444,
FT ECO:0000305|PubMed:9020148"
FT SITE 26
FT /note="Important for binding Kv1.1, Kv1.2 and key residue
FT for binding Kv1.3"
FT /evidence="ECO:0000305|PubMed:10585444,
FT ECO:0000305|PubMed:9020148"
FT SITE 27
FT /note="Important for binding Kv1.3"
FT /evidence="ECO:0000305|PubMed:10585444"
FT DISULFID 2..37
FT /evidence="ECO:0000269|PubMed:9020148,
FT ECO:0000269|PubMed:9063464"
FT DISULFID 11..30
FT /evidence="ECO:0000269|PubMed:9020148,
FT ECO:0000269|PubMed:9063464"
FT DISULFID 20..34
FT /evidence="ECO:0000269|PubMed:9020148,
FT ECO:0000269|PubMed:9063464"
FT MUTAGEN 1
FT /note="V->A: No change in affinity on Kv1.1 and on Kv1.3.
FT Small increase in affinity on Kv1.2."
FT /evidence="ECO:0000269|PubMed:10585444"
FT MUTAGEN 3
FT /note="R->A: Small decrease in affinity on Kv1.1, Kv1.2 and
FT Kv1.3."
FT /evidence="ECO:0000269|PubMed:10585444"
FT MUTAGEN 4
FT /note="D->A: Is not properly oxidized."
FT /evidence="ECO:0000269|PubMed:10585444"
FT MUTAGEN 5
FT /note="W->A: Small decrease in affinity on Kv1.1 and on
FT Kv1.2. No change in affinity on Kv1.3."
FT /evidence="ECO:0000269|PubMed:10585444"
FT MUTAGEN 5
FT /note="W->Y: No change in affinity on Kv1.1, Kv1.2 and
FT Kv1.6; when associated with F-26. Important decrease in
FT affinity on Kv1.2, and no change in affinity on Kv1.1 and
FT Kv1.6; when associated with A-6 and F-26."
FT /evidence="ECO:0000269|PubMed:11707459"
FT MUTAGEN 6
FT /note="F->A: No change in affinity on Kv1.1. >500-fold
FT decrease in affinity on Kv1.2. 20-100-fold decrease in
FT affinity on Kv1.3. 46-fold decrease in ability to compete
FT with alpha-dendrotoxin. Important decrease in affinity on
FT Kv1.2, and no change in affinity on Kv1.1 and Kv1.6; when
FT associated with Y-5 and F-26."
FT /evidence="ECO:0000269|PubMed:10585444,
FT ECO:0000269|PubMed:11707459, ECO:0000269|PubMed:9020148"
FT MUTAGEN 7
FT /note="K->A: Small decrease in affinity on Kv1.1 and on
FT Kv1.2. 20-100-fold decrease in affinity on Kv1.3."
FT /evidence="ECO:0000269|PubMed:10585444"
FT MUTAGEN 8
FT /note="E->A: No change in affinity on Kv1.1. Small increase
FT in affinity on Kv1.2. Small decrease in affinity on Kv1.3."
FT /evidence="ECO:0000269|PubMed:10585444"
FT MUTAGEN 9
FT /note="T->A: Small decrease in affinity on Kv1.1 and on
FT Kv1.3. Small increase in affinity on Kv1.2."
FT /evidence="ECO:0000269|PubMed:10585444"
FT MUTAGEN 12
FT /note="R->A: Small decrease in affinity on Kv1.1 and on
FT Kv1.3. 5-20-fold decrease in affinity on Kv1.2."
FT /evidence="ECO:0000269|PubMed:10585444"
FT MUTAGEN 13
FT /note="H->A: Small decrease in affinity on Kv1.1. 5-20-fold
FT decrease in affinity on Kv1.2 and on Kv1.3. 5.6-fold
FT decrease in ability to compete with alpha-dendrotoxin."
FT /evidence="ECO:0000269|PubMed:10585444,
FT ECO:0000269|PubMed:9020148"
FT MUTAGEN 15
FT /note="K->A: Small decrease in affinity on Kv1.1, Kv1.2 and
FT Kv1.3."
FT /evidence="ECO:0000269|PubMed:10585444"
FT MUTAGEN 16
FT /note="S->A: Small decrease in affinity on Kv1.1 and on
FT Kv1.3. No change in affinity on Kv1.2."
FT /evidence="ECO:0000269|PubMed:10585444"
FT MUTAGEN 17
FT /note="L->A: Small decrease in affinity on Kv1.1. No change
FT in affinity on Kv1.2. 5-20-fold decrease in affinity on
FT Kv1.3."
FT /evidence="ECO:0000269|PubMed:10585444"
FT MUTAGEN 19
FT /note="N->A: 20-fold decrease in affinity on Kv1.1. Small
FT decrease in affinity on Kv1.2. 20-100-fold decrease in
FT affinity on Kv1.3."
FT /evidence="ECO:0000269|PubMed:10585444"
FT MUTAGEN 21
FT /note="R->A: Small decrease in affinity on Kv1.1, Kv1.2 and
FT Kv1.3."
FT /evidence="ECO:0000269|PubMed:10585444"
FT MUTAGEN 22
FT /note="T->A: Small decrease in affinity on Kv1.1. Small
FT increase in affinity on Kv1.2. 5-20-fold decrease in
FT affinity on Kv1.3."
FT /evidence="ECO:0000269|PubMed:10585444"
FT MUTAGEN 23
FT /note="S->A: 5-20-fold decrease in affinity on Kv1.1 and on
FT Kv1.2. 20-100-fold decrease in affinity on Kv1.3. 8.3-fold
FT decrease in ability to compete with alpha-dendrotoxin."
FT /evidence="ECO:0000269|PubMed:10585444,
FT ECO:0000269|PubMed:9020148"
FT MUTAGEN 24
FT /note="Q->A: 5-20-fold decrease in affinity on Kv1.1. No
FT change in affinity on Kv1.2. 20-100-fold decrease in
FT affinity on Kv1.3."
FT /evidence="ECO:0000269|PubMed:10585444"
FT MUTAGEN 25
FT /note="K->A: 60-fold decrease in affinity on Kv1.1. >500-
FT fold decrease in affinity on Kv1.2. 20-100-fold decrease in
FT affinity on Kv1.3. >80-fold decrease in ability to compete
FT with alpha-dendrotoxin. 214-fold decrease in affinity on
FT Kv1.1, 23000-fold affinity decrease on Kv1.2 and 1580-fold
FT decrease in affinity on Kv1.3; when associated with A-26."
FT /evidence="ECO:0000269|PubMed:10585444,
FT ECO:0000269|PubMed:9020148"
FT MUTAGEN 26
FT /note="Y->A: 20-fold decrease in affinity on Kv1.1. >20-
FT fold decrease in affinity on Kv1.2. 20-100-fold decrease in
FT affinity on Kv1.3. 28-fold decrease in ability to compete
FT with alpha-dendrotoxin. 214-fold decrease in affinity on
FT Kv1.1, 23000-fold affinity decrease on Kv1.2 and 1580-fold
FT decrease in affinity on Kv1.3; when associated with A-25."
FT /evidence="ECO:0000269|PubMed:10585444,
FT ECO:0000269|PubMed:9020148"
FT MUTAGEN 26
FT /note="Y->F: No change in affinity on Kv1.1, Kv1.2 and
FT Kv1.6; when associated with Y-5. Important decrease in
FT affinity on Kv1.2, and no change in affinity on Kv1.1 and
FT Kv1.6; when associated with Y-5 and A-6."
FT /evidence="ECO:0000269|PubMed:11707459"
FT MUTAGEN 27
FT /note="R->A: Small decrease in affinity on Kv1.1 and on
FT Kv1.2. 5-20-fold decrease in affinity on Kv1.3."
FT /evidence="ECO:0000269|PubMed:10585444"
FT MUTAGEN 29
FT /note="N->A: Shows distorsions in the dichroic spectrum. 5-
FT 20-fold decrease in affinity on Kv1.1 and on Kv1.3. Small
FT decrease in affinity on Kv1.2."
FT /evidence="ECO:0000269|PubMed:10585444"
FT MUTAGEN 32
FT /note="K->A: Shows distorsions in the dichroic spectrum.
FT Small decrease in affinity on Kv1.1 and on Kv1.3. No change
FT in affinity on Kv1.2."
FT /evidence="ECO:0000269|PubMed:10585444"
FT MUTAGEN 33
FT /note="T->A: Shows distorsions in the dichroic spectrum. No
FT change in affinity on Kv1.1. Small decrease in affinity on
FT Kv1.2 and on Kv1.3."
FT /evidence="ECO:0000269|PubMed:10585444"
FT MUTAGEN 35
FT /note="E->A: Shows distorsions in the dichroic spectrum. No
FT change in affinity on Kv1.1 and on Kv1.3. Small increase in
FT affinity on Kv1.2."
FT /evidence="ECO:0000269|PubMed:10585444"
FT MUTAGEN 36
FT /note="L->A: Shows distorsions in the dichroic spectrum.
FT Small decrease in affinity on Kv1.1 and on Kv1.2. 5-20-fold
FT decrease in affinity on Kv1.3."
FT /evidence="ECO:0000269|PubMed:10585444"
FT HELIX 8..17
FT /evidence="ECO:0007829|PDB:1BGK"
FT TURN 19..22
FT /evidence="ECO:0007829|PDB:1BGK"
FT HELIX 24..27
FT /evidence="ECO:0007829|PDB:1BGK"
FT TURN 28..35
FT /evidence="ECO:0007829|PDB:1BGK"
SQ SEQUENCE 37 AA; 4282 MW; 1E1315690D28958F CRC64;
VCRDWFKETA CRHAKSLGNC RTSQKYRANC AKTCELC
