ID   VKT1_ANESU              Reviewed;          58 AA.
AC   Q9TWG0;
DT   23-NOV-2004, integrated into UniProtKB/Swiss-Prot.
DT   01-MAY-2000, sequence version 1.
DT   25-MAY-2022, entry version 83.
DE   RecName: Full=KappaPI-actitoxin-Avd3b {ECO:0000303|PubMed:22683676};
DE            Short=KappaPI-AITX-Avd3b {ECO:0000303|PubMed:22683676};
DE   AltName: Full=Kunitz-type serine protease inhibitor kalicludine-1 {ECO:0000303|PubMed:7559645};
DE            Short=AsKC1 {ECO:0000303|PubMed:7559645};
OS   Anemonia sulcata (Mediterranean snakelocks sea anemone).
OC   Eukaryota; Metazoa; Cnidaria; Anthozoa; Hexacorallia; Actiniaria;
OC   Actiniidae; Anemonia.
OX   NCBI_TaxID=6108;
RN   [1]
RP   PROTEIN SEQUENCE, AND FUNCTION.
RX   PubMed=7559645; DOI=10.1074/jbc.270.42.25121;
RA   Schweitz H., Bruhn T., Guillemare E., Moinier D., Lancelin J.-M.,
RA   Beress L., Lazdunski M.;
RT   "Kalicludines and kaliseptine. Two different classes of sea anemone toxins
RT   for voltage sensitive K+ channels.";
RL   J. Biol. Chem. 270:25121-25126(1995).
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: Dual-function toxin that inhibits both the serine protease
CC       trypsin (Kd<30 nM) and voltage-gated potassium channels Kv1.2/KCNA2
CC       (IC(50)=2800 nM). {ECO:0000269|PubMed:7559645}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000305|PubMed:7559645}. Nematocyst
CC       {ECO:0000305}.
CC   -!- SIMILARITY: Belongs to the venom Kunitz-type family. Sea anemone type 2
CC       potassium channel toxin subfamily. {ECO:0000305}.
CC   -!- CAUTION: Opinions are divided on whether Anemonia viridis (Forsskal,
CC       1775) and Anemonia sulcata (Pennant, 1777) are separate species.
CC       {ECO:0000305}.
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DR   AlphaFoldDB; Q9TWG0; -.
DR   SMR; Q9TWG0; -.
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:0004867; F:serine-type endopeptidase inhibitor activity; IEA:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   CDD; cd00109; KU; 1.
DR   Gene3D; 4.10.410.10; -; 1.
DR   InterPro; IPR002223; Kunitz_BPTI.
DR   InterPro; IPR036880; Kunitz_BPTI_sf.
DR   InterPro; IPR020901; Prtase_inh_Kunz-CS.
DR   Pfam; PF00014; Kunitz_BPTI; 1.
DR   PRINTS; PR00759; BASICPTASE.
DR   SMART; SM00131; KU; 1.
DR   SUPFAM; SSF57362; SSF57362; 1.
DR   PROSITE; PS00280; BPTI_KUNITZ_1; 1.
DR   PROSITE; PS50279; BPTI_KUNITZ_2; 1.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Disulfide bond; Ion channel impairing toxin;
KW   Nematocyst; Potassium channel impairing toxin; Protease inhibitor;
KW   Secreted; Serine protease inhibitor; Toxin;
KW   Voltage-gated potassium channel impairing toxin.
FT   CHAIN           1..58
FT                   /note="KappaPI-actitoxin-Avd3b"
FT                   /evidence="ECO:0000269|PubMed:7559645"
FT                   /id="PRO_0000155412"
FT   DOMAIN          5..55
FT                   /note="BPTI/Kunitz inhibitor"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT   SITE            15..16
FT                   /note="Reactive bond for trypsin"
FT                   /evidence="ECO:0000250|UniProtKB:P31713"
FT   DISULFID        5..55
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT   DISULFID        14..38
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT   DISULFID        30..51
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
SQ   SEQUENCE   58 AA;  6691 MW;  253E068896B4BDCD CRC64;
     INKDCLLPMD VGRCRASHPR YYYNSSSKRC EKFIYGGCRG NANNFHTLEE CEKVCGVR