ID   K1A_CRYAD               Reviewed;          75 AA.
AC   E2S064;
DT   19-MAR-2014, integrated into UniProtKB/Swiss-Prot.
DT   11-JAN-2011, sequence version 1.
DT   25-MAY-2022, entry version 24.
DE   RecName: Full=Kappa-thalatoxin-Cad2a {ECO:0000305};
DE            Short=Kappa-TATX-Cad2a {ECO:0000305};
DE   AltName: Full=Kappa1.3-thalatoxin-Ca1a {ECO:0000303|PubMed:21339955};
DE            Short=Kappa-TATX-Ca1a {ECO:0000305|PubMed:21339955};
DE            Short=Kappa1.3-TLTX-Ca1a {ECO:0000303|PubMed:21339955};
DE   AltName: Full=Potassium channel peptide toxin ca-k {ECO:0000312|EMBL:BAJ23161.1};
DE            Short=CaK {ECO:0000305};
DE   Flags: Precursor;
OS   Cryptodendrum adhaesivum (Adhesive sea anemone).
OC   Eukaryota; Metazoa; Cnidaria; Anthozoa; Hexacorallia; Actiniaria;
OC   Nynantheae; Thalassianthidae; Cryptodendrum.
OX   NCBI_TaxID=659513;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RX   PubMed=21339955; DOI=10.3390/md8122893;
RA   Yamaguchi Y., Hasegawa Y., Honma T., Nagashima Y., Shiomi K.;
RT   "Screening and cDNA cloning of Kv1 potassium channel toxins in sea
RT   anemones.";
RL   Mar. Drugs 8:2893-2905(2010).
CC   -!- FUNCTION: Inhibits voltage-gated potassium channels (Kv) with higher
CC       potency for Kv1.1/KCNA1 and Kv1.3/KCNA3.
CC       {ECO:0000250|UniProtKB:P29187}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000305}. Nematocyst {ECO:0000305}.
CC   -!- MISCELLANEOUS: In PubMed:21339955, this protein is called kappa-TLTX-
CC       Hh1a. The TATX abbreviation is given to this protein since the
CC       abbreviation TLTX was already given to a spider family. {ECO:0000305}.
CC   -!- SIMILARITY: Belongs to the sea anemone type 1 potassium channel toxin
CC       family. Type 1a subfamily. {ECO:0000305}.
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DR   EMBL; AB595207; BAJ23161.1; -; mRNA.
DR   AlphaFoldDB; E2S064; -.
DR   SMR; E2S064; -.
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   PROSITE; PS51670; SHKT; 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..22
FT                   /evidence="ECO:0000255"
FT   PROPEP          23..40
FT                   /evidence="ECO:0000250"
FT                   /id="PRO_0000425835"
FT   PEPTIDE         41..75
FT                   /note="Kappa-thalatoxin-Cad2a"
FT                   /evidence="ECO:0000250|UniProtKB:P29187"
FT                   /id="PRO_0000425836"
FT   DOMAIN          43..75
FT                   /note="ShKT"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01005"
FT   SITE            47
FT                   /note="Important residue for binding Kv1.3/KCNA3"
FT                   /evidence="ECO:0000250|UniProtKB:P29187"
FT   SITE            49
FT                   /note="Important residue for binding Kv1.3/KCNA3"
FT                   /evidence="ECO:0000250|UniProtKB:P29187"
FT   SITE            51
FT                   /note="Important residue for binding Kv1.3/KCNA3"
FT                   /evidence="ECO:0000250|UniProtKB:P29187"
FT   SITE            60
FT                   /note="Important residue for binding Kv1.3/KCNA3"
FT                   /evidence="ECO:0000250|UniProtKB:P29187"
FT   SITE            61
FT                   /note="Important residue for binding Kv1.3/KCNA3"
FT                   /evidence="ECO:0000250|UniProtKB:P29187"
FT   SITE            62
FT                   /note="Key residue for binding both Kv1.2/KCNA2 and
FT                   Kv1.3/KCNA3 (occludes the channel pore like a cork in a
FT                   bottle)"
FT                   /evidence="ECO:0000250|UniProtKB:P29187"
FT   SITE            63
FT                   /note="Important residue for binding Kv1.3/KCNA3"
FT                   /evidence="ECO:0000250|UniProtKB:P29187"
FT   SITE            67
FT                   /note="Important residue for binding Kv1.3/KCNA3"
FT                   /evidence="ECO:0000250|UniProtKB:P29187"
FT   DISULFID        43..75
FT                   /evidence="ECO:0000250|UniProtKB:P29187"
FT   DISULFID        52..68
FT                   /evidence="ECO:0000250|UniProtKB:P29187"
FT   DISULFID        57..72
FT                   /evidence="ECO:0000250|UniProtKB:P29187"
SQ   SEQUENCE   75 AA;  8612 MW;  3AD2ED89BB9B56FA CRC64;
     MKFQMIAAVL LIAFCLCVVV TARMELQDVE DMKNGSFQKR RTCIDTIPKS RCTAFQCKNS
     MKYRLSFCRK TCGTC