VKT3_STIHA
ID VKT3_STIHA Reviewed; 81 AA.
AC B1B5I8;
DT 22-JUL-2008, integrated into UniProtKB/Swiss-Prot.
DT 29-APR-2008, sequence version 1.
DT 25-MAY-2022, entry version 46.
DE RecName: Full=KappaPI-stichotoxin-Shd2a {ECO:0000303|PubMed:22683676};
DE Short=KappaPI-SHTX-Shd2a {ECO:0000303|PubMed:22683676};
DE AltName: Full=Kunitz-type protease inhibitor and potassium channel toxin SHTX III {ECO:0000303|PubMed:18243416};
DE AltName: Full=Kunitz-type protease inhibitor and potassium channel toxin SHTX-3;
DE Flags: Precursor;
OS Stichodactyla haddoni (Saddle carpet anemone) (Haddon's sea anemone).
OC Eukaryota; Metazoa; Cnidaria; Anthozoa; Hexacorallia; Actiniaria;
OC Stichodactylidae; Stichodactyla.
OX NCBI_TaxID=475174;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA], PROTEIN SEQUENCE OF 20-73, FUNCTION, MASS
RP SPECTROMETRY, AND TOXIC DOSE.
RX PubMed=18243416; DOI=10.1016/j.peptides.2007.12.010;
RA Honma T., Kawahata S., Ishida M., Nagai H., Nagashima Y., Shiomi K.;
RT "Novel peptide toxins from the sea anemone Stichodactyla haddoni.";
RL Peptides 29:536-544(2008).
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 and voltage-gated potassium channels (Kv).
CC {ECO:0000269|PubMed:18243416}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000305|PubMed:18243416}.
CC Nematocyst {ECO:0000305}.
CC -!- MASS SPECTROMETRY: Mass=7035.0; Method=MALDI;
CC Evidence={ECO:0000269|PubMed:18243416};
CC -!- TOXIC DOSE: PD(50) is 183 ug/kg into crabs.
CC {ECO:0000269|PubMed:18243416}.
CC -!- SIMILARITY: Belongs to the venom Kunitz-type family. Sea anemone type 2
CC potassium channel toxin subfamily. {ECO:0000305}.
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DR EMBL; AB362569; BAG12824.1; -; mRNA.
DR AlphaFoldDB; B1B5I8; -.
DR SMR; B1B5I8; -.
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; Signal; Toxin;
KW Voltage-gated potassium channel impairing toxin.
FT SIGNAL 1..19
FT /evidence="ECO:0000269|PubMed:18243416"
FT CHAIN 20..81
FT /note="KappaPI-stichotoxin-Shd2a"
FT /evidence="ECO:0000305|PubMed:18243416"
FT /id="PRO_0000344522"
FT DOMAIN 27..77
FT /note="BPTI/Kunitz inhibitor"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT SITE 37..38
FT /note="Reactive bond for trypsin"
FT /evidence="ECO:0000250|UniProtKB:P31713"
FT DISULFID 27..77
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT DISULFID 36..60
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT DISULFID 52..73
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
SQ SEQUENCE 81 AA; 9111 MW; 349F272417B3A1F0 CRC64;
MAKLYFLLCL ALVACLTMAT EEMPALCHLQ PDVPKCRGYF PRYYYNPEVG KCEQFIYGGC
GGNKNNFVSF EACRATCIIP L
