VKT2J_HETCR
ID VKT2J_HETCR Reviewed; 72 AA.
AC A0A6B7FA07;
DT 02-JUN-2021, integrated into UniProtKB/Swiss-Prot.
DT 17-JUN-2020, sequence version 1.
DT 25-MAY-2022, entry version 9.
DE RecName: Full=PI-stichotoxin-Hcr2j {ECO:0000305};
DE Short=PI-SHTX-Hcr2j {ECO:0000305};
DE AltName: Full=Kunitz-peptide HCIQ4c7 {ECO:0000303|PubMed:32144281};
DE Flags: Precursor; Fragment;
GN Name=iq4c7 {ECO:0000303|PubMed:32144281};
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 NUCLEOTIDE SEQUENCE [MRNA], AND RECOMBINANT EXPRESSION.
RX PubMed=32144281; DOI=10.1038/s41598-020-61034-x;
RA Kvetkina A., Leychenko E., Chausova V., Zelepuga E., Chernysheva N.,
RA Guzev K., Pislyagin E., Yurchenko E., Menchinskaya E., Aminin D.,
RA Kaluzhskiy L., Ivanov A., Peigneur S., Tytgat J., Kozlovskaya E.,
RA Isaeva M.;
RT "A new multigene HCIQ subfamily from the sea anemone Heteractis crispa
RT encodes Kunitz-peptides exhibiting neuroprotective activity against 6-
RT hydroxydopamine.";
RL Sci. Rep. 10:4205-4205(2020).
CC -!- FUNCTION: Serine protease inhibitor that acts on trypsin (Ki=190 nM)
CC and to elastase (PubMed:32144281). Does not bind to alpha-chymotrypsin,
CC cathepsin G, and kallikrein (PubMed:32144281).
CC {ECO:0000269|PubMed:32144281}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000250|UniProtKB:P31713}.
CC Nematocyst {ECO:0000250|UniProtKB:P31713}.
CC -!- MISCELLANEOUS: Does not show activity on all potassium channel tested
CC (Kv1.1/KCNA1, Kv1.2/KCNA2, Kv1.3/KCNA3, Kv1.4/KCNA4, Kv1.5/KCNA5,
CC Kv1.6/KCNA8, Shaker IR, and Kv11.1/KCNH2/ERG1).
CC {ECO:0000269|PubMed:32144281}.
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; MH249939; QBA29488.1; -; mRNA.
DR AlphaFoldDB; A0A6B7FA07; -.
DR SMR; A0A6B7FA07; -.
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; 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 2: Evidence at transcript level;
KW Cleavage on pair of basic residues; Disulfide bond; Nematocyst;
KW Protease inhibitor; Secreted; Serine protease inhibitor; Signal.
FT SIGNAL <1..9
FT /evidence="ECO:0000305"
FT PROPEP 10..17
FT /evidence="ECO:0000305|PubMed:32144281"
FT /id="PRO_0000453029"
FT CHAIN 18..72
FT /note="PI-stichotoxin-Hcr2j"
FT /evidence="ECO:0000305|PubMed:32144281"
FT /id="PRO_0000453030"
FT DOMAIN 20..70
FT /note="BPTI/Kunitz inhibitor"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00031"
FT SITE 30..31
FT /note="Reactive bond for trypsin"
FT /evidence="ECO:0000250|UniProtKB:P31713"
FT SITE 61
FT /note="Important for the stabilization when complexed with
FT trypsin"
FT /evidence="ECO:0000250|UniProtKB:P0DMJ5"
FT DISULFID 20..70
FT /evidence="ECO:0000250|UniProtKB:P31713"
FT DISULFID 29..53
FT /evidence="ECO:0000250|UniProtKB:P31713"
FT DISULFID 45..66
FT /evidence="ECO:0000250|UniProtKB:P31713"
FT NON_TER 1
FT /evidence="ECO:0000312|EMBL:QBA29488.1"
SQ SEQUENCE 72 AA; 8206 MW; 2F106F7691DE710D CRC64;
GFYFRSIQGF YFKRIQGNIC SEPKKVGRCR ESFPRFYFDS ETGKCTPFIY GGCGGNGNNF
ETLHACRAIC RA
