ID   BDS3B_BUNGR             Reviewed;          74 AA.
AC   G0W2H9;
DT   22-JUL-2015, integrated into UniProtKB/Swiss-Prot.
DT   19-OCT-2011, sequence version 1.
DT   25-MAY-2022, entry version 21.
DE   RecName: Full=U-actitoxin-Bgr3b {ECO:0000303|PubMed:22683676};
DE            Short=U-AITX-Bgr3b {ECO:0000303|PubMed:22683676};
DE   AltName: Full=U-AITX-Bg1c {ECO:0000303|PubMed:22015268};
DE   Flags: Precursor;
OS   Bunodosoma granuliferum (Red warty sea anemone).
OC   Eukaryota; Metazoa; Cnidaria; Anthozoa; Hexacorallia; Actiniaria;
OC   Actiniidae; Bunodosoma.
OX   NCBI_TaxID=31164;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
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   [2]
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).
CC   -!- FUNCTION: Potently and selectively inhibits voltage-gated potassium
CC       channels Kv11/KCNH/ERG. Acts as a gating-modifier toxin that shifts the
CC       voltage-dependence of ERG activation in the positive direction and
CC       suppresses its current amplitudes elicited by strong depolarizing
CC       pulses that maximally activate the channels.
CC       {ECO:0000250|UniProtKB:P61541}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000305}. Nematocyst {ECO:0000305}.
CC   -!- SIMILARITY: Belongs to the sea anemone type 3 (BDS) potassium channel
CC       toxin family. {ECO:0000305}.
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DR   EMBL; HE577146; CCC86604.1; -; mRNA.
DR   AlphaFoldDB; G0W2H9; -.
DR   SMR; G0W2H9; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0042151; C:nematocyst; 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; 2.20.20.10; -; 1.
DR   InterPro; IPR012414; BDS_K_chnl_tox.
DR   InterPro; IPR023355; Myo_ane_neurotoxin_sf.
DR   Pfam; PF07936; Defensin_4; 1.
PE   3: Inferred from homology;
KW   Cleavage on pair of basic residues; Disulfide bond;
KW   Ion channel impairing toxin; Nematocyst; Neurotoxin;
KW   Potassium channel impairing toxin; Secreted; Signal; Toxin;
KW   Voltage-gated potassium channel impairing toxin.
FT   SIGNAL          1..21
FT                   /evidence="ECO:0000255"
FT   PROPEP          22..29
FT                   /evidence="ECO:0000250|UniProtKB:G0W2H8"
FT                   /id="PRO_0000433589"
FT   CHAIN           32..74
FT                   /note="U-actitoxin-Bgr3b"
FT                   /id="PRO_0000433590"
FT   DISULFID        35..68
FT                   /evidence="ECO:0000250|UniProtKB:P61541"
FT   DISULFID        37..61
FT                   /evidence="ECO:0000250|UniProtKB:P61541"
FT   DISULFID        51..69
FT                   /evidence="ECO:0000250|UniProtKB:P61541"
SQ   SEQUENCE   74 AA;  8345 MW;  9A220E28D70CB782 CRC64;
     MSARRFLFLL VVTSLIAASL AAPKDVQMTK RGTPCWCGQT KGVYWYWMRK CPSGYGYTGN
     CYHFMGRCCY PAGS