ID   VKT2A_HETCR             Reviewed;          56 AA.
AC   P16344;
DT   01-AUG-1990, integrated into UniProtKB/Swiss-Prot.
DT   01-AUG-1990, sequence version 1.
DT   27-MAR-2024, entry version 87.
DE   RecName: Full=PI-stichotoxin-Hcr2a {ECO:0000303|PubMed:22683676};
DE            Short=PI-SHTX-Hcr2a {ECO:0000303|PubMed:22683676};
DE   AltName: Full=Kunitz-type trypsin inhibitor IV {ECO:0000303|Ref.1};
DE            Short=Jn-IV;
OS   Heteractis crispa (Leathery sea anemone) (Radianthus macrodactylus).
OC   Eukaryota; Metazoa; Cnidaria; Anthozoa; Hexacorallia; Actiniaria;
OC   Stichodactylidae; Heteractis.
OX   NCBI_TaxID=175771;
RN   [1]
RP   PROTEIN SEQUENCE, FUNCTION, AND SUBCELLULAR LOCATION.
RA   Zykova T.A., Vinokurov L.M., Markova L.F., Kozlovskaya E.P., Elyakov G.B.;
RT   "Amino-acid sequence of trypsin inhibitor IV from Radiantis
RT   macrodactylus.";
RL   Bioorg. Khim. 11:293-301(1985).
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: Serine protease inhibitor that acts on trypsin.
CC       {ECO:0000269|Ref.1}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|Ref.1}. 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   ---------------------------------------------------------------------------
CC   Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC   Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC   ---------------------------------------------------------------------------
DR   PIR; JN0380; JN0380.
DR   AlphaFoldDB; P16344; -.
DR   SMR; P16344; -.
DR   MEROPS; I02.061; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0042151; C:nematocyst; IEA:UniProtKB-SubCell.
DR   GO; GO:0004867; F:serine-type endopeptidase inhibitor activity; IEA:UniProtKB-KW.
DR   CDD; cd22618; Kunitz_SHPI; 1.
DR   Gene3D; 4.10.410.10; Pancreatic trypsin inhibitor Kunitz domain; 1.
DR   InterPro; IPR002223; Kunitz_BPTI.
DR   InterPro; IPR036880; Kunitz_BPTI_sf.
DR   PANTHER; PTHR10083; KUNITZ-TYPE PROTEASE INHIBITOR-RELATED; 1.
DR   PANTHER; PTHR10083:SF217; PROTEIN CBG23496; 1.
DR   Pfam; PF00014; Kunitz_BPTI; 1.
DR   PRINTS; PR00759; BASICPTASE.
DR   SMART; SM00131; KU; 1.
DR   SUPFAM; SSF57362; BPTI-like; 1.
DR   PROSITE; PS50279; BPTI_KUNITZ_2; 1.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Disulfide bond; Nematocyst; Protease inhibitor;
KW   Secreted; Serine protease inhibitor.
FT   CHAIN           1..56
FT                   /note="PI-stichotoxin-Hcr2a"
FT                   /evidence="ECO:0000269|Ref.1"
FT                   /id="PRO_0000155418"
FT   DOMAIN          4..54
FT                   /note="BPTI/Kunitz inhibitor"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT   SITE            14..15
FT                   /note="Reactive bond for trypsin"
FT                   /evidence="ECO:0000250|UniProtKB:P31713"
FT   DISULFID        4..54
FT                   /evidence="ECO:0000250|UniProtKB:P31713"
FT   DISULFID        13..37
FT                   /evidence="ECO:0000250|UniProtKB:P31713"
FT   DISULFID        29..50
FT                   /evidence="ECO:0000250|UniProtKB:P31713"
SQ   SEQUENCE   56 AA;  6172 MW;  68374D2025B841C0 CRC64;
     GSICLEPKVV GPCTAYFPRF YFDSETGKCT PFIYGGCEGN SYVDEKLHAC RAICRA
//