ID   PCE_TACTR               Reviewed;         375 AA.
AC   P21902;
DT   01-MAY-1991, integrated into UniProtKB/Swiss-Prot.
DT   01-MAY-1991, sequence version 1.
DT   02-SEP-2026, entry version 124.
DE   RecName: Full=Proclotting enzyme;
DE            EC=3.4.21.86 {ECO:0000269|PubMed:2266134, ECO:0000269|PubMed:977558, ECO:0000305|PubMed:7822280, ECO:0000305|PubMed:7822328, ECO:0000305|PubMed:8798603};
DE   Contains:
DE     RecName: Full=Proclotting enzyme light chain {ECO:0000303|PubMed:2266134};
DE   Contains:
DE     RecName: Full=Proclotting enzyme heavy chain {ECO:0000303|PubMed:2266134};
DE   Flags: Precursor;
OS   Tachypleus tridentatus (Japanese horseshoe crab).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Merostomata;
OC   Xiphosura; Limulidae; Tachypleus.
OX   NCBI_TaxID=6853;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], PARTIAL PROTEIN SEQUENCE, FUNCTION, CATALYTIC
RP   ACTIVITY, SUBUNIT, SUBCELLULAR LOCATION, TISSUE SPECIFICITY, DOMAIN,
RP   PROTEOLYTIC CLEAVAGE, DISULFIDE BONDS, GLYCOSYLATION AT ASN-122; ASN-235
RP   AND ASN-304, AND PYROGLUTAMATE FORMATION AT GLN-30.
RC   TISSUE=Hemocyte;
RX   PubMed=2266134; DOI=10.1016/s0021-9258(18)45722-5;
RA   Muta T., Hashimoto R., Miyata T., Nishimura H., Toh Y., Iwanaga S.;
RT   "Proclotting enzyme from horseshoe crab hemocytes. cDNA cloning, disulfide
RT   locations, and subcellular localization.";
RL   J. Biol. Chem. 265:22426-22433(1990).
RN   [2]
RP   FUNCTION, AND CATALYTIC ACTIVITY.
RX   PubMed=977558; DOI=10.1093/oxfordjournals.jbchem.a131323;
RA   Nakamura S., Takagi T., Iwanaga S., Niwa M., Takahashi K.;
RT   "A clottable protein (coagulogen) of horseshoe crab hemocytes. Structural
RT   change of its polypeptide chain during gel formation.";
RL   J. Biochem. 80:649-652(1976).
RN   [3]
RP   CATALYTIC ACTIVITY, SUBUNIT, PROTEOLYTIC CLEAVAGE, DISULFIDE BOND, AND
RP   GLYCOSYLATION.
RX   PubMed=4030738; DOI=10.1093/oxfordjournals.jbchem.a135213;
RA   Nakamura T., Morita T., Iwanaga S.;
RT   "Intracellular proclotting enzyme in limulus (Tachypleus tridentatus)
RT   hemocytes: its purification and properties.";
RL   J. Biochem. 97:1561-1574(1985).
RN   [4]
RP   CATALYTIC ACTIVITY, ACTIVITY REGULATION, SUBUNIT, AND TISSUE SPECIFICITY.
RX   PubMed=7822280; DOI=10.1074/jbc.270.2.558;
RA   Miura Y., Kawabata S., Wakamiya Y., Nakamura T., Iwanaga S.;
RT   "A limulus intracellular coagulation inhibitor type 2. Purification,
RT   characterization, cDNA cloning, and tissue localization.";
RL   J. Biol. Chem. 270:558-565(1995).
RN   [5]
RP   FUNCTION, CATALYTIC ACTIVITY, AND PROTEOLYTIC CLEAVAGE.
RX   PubMed=7822328; DOI=10.1074/jbc.270.2.892;
RA   Muta T., Seki N., Takaki Y., Hashimoto R., Oda T., Iwanaga A., Tokunaga F.,
RA   Iwanaga S.;
RT   "Purified horseshoe crab factor G. Reconstitution and characterization of
RT   the (1-->3)-beta-D-glucan-sensitive serine protease cascade.";
RL   J. Biol. Chem. 270:892-897(1995).
RN   [6]
RP   CATALYTIC ACTIVITY, AND ACTIVITY REGULATION.
RX   PubMed=8798603; DOI=10.1074/jbc.271.39.23768;
RA   Agarwala K.L., Kawabata S., Miura Y., Kuroki Y., Iwanaga S.;
RT   "Limulus intracellular coagulation inhibitor type 3. Purification,
RT   characterization, cDNA cloning, and tissue localization.";
RL   J. Biol. Chem. 271:23768-23774(1996).
CC   -!- FUNCTION: This enzyme is closely associated with an endotoxin-sensitive
CC       hemolymph coagulation system in limulus (PubMed:2266134). Its active
CC       form catalyzes the conversion of coagulogen to insoluble coagulin gel
CC       (PubMed:7822328, PubMed:977558). {ECO:0000269|PubMed:2266134,
CC       ECO:0000269|PubMed:7822328, ECO:0000269|PubMed:977558}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Selective cleavage of 18-Arg-|- and 47-Arg-|- bonds in
CC         coagulogen to form coagulin and fragments.; EC=3.4.21.86;
CC         Evidence={ECO:0000269|PubMed:977558, ECO:0000305|PubMed:4030738,
CC         ECO:0000305|PubMed:7822280, ECO:0000305|PubMed:7822328,
CC         ECO:0000305|PubMed:8798603};
CC   -!- ACTIVITY REGULATION: Inhibited by intracellular coagulation inhibitor
CC       2/LICI-2 and to a lesser extent by intracellular coagulation inhibitor
CC       3/LICI-3. {ECO:0000269|PubMed:7822280, ECO:0000269|PubMed:8798603}.
CC   -!- SUBUNIT: In the active form, heterodimer of a light chain and a heavy
CC       chain; disulfide-linked (PubMed:2266134, PubMed:7822280). Forms a
CC       covalent heterodimer with intracellular coagulation inhibitor 2/LICI-2
CC       (PubMed:7822280). {ECO:0000269|PubMed:2266134,
CC       ECO:0000269|PubMed:7822280}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasmic vesicle, secretory vesicle
CC       {ECO:0000269|PubMed:2266134}. Secreted {ECO:0000269|PubMed:2266134}.
CC       Note=Secreted in hemolymph probably upon bacterial lipopolysaccharide
CC       (LPS) stimulation. {ECO:0000303|PubMed:2266134}.
CC   -!- TISSUE SPECIFICITY: Expressed in hemocytes (at protein level).
CC       {ECO:0000269|PubMed:2266134, ECO:0000269|PubMed:7822280}.
CC   -!- DOMAIN: The clip domain consists of 35-55 residues which are 'knitted'
CC       together usually by 3 conserved disulfide bonds forming a clip-like
CC       compact structure. {ECO:0000255|PROSITE-ProRule:PRU01236,
CC       ECO:0000269|PubMed:2266134}.
CC   -!- PTM: Proteolytically cleaved into its mature active form by serine
CC       protease factor B (PubMed:2266134, PubMed:4030738). Cleavage produces a
CC       25 kDa light chain containing the CLIP domain and a catalytic 31 kDa
CC       heavy chain which remain covalently associated through an interchain
CC       disulfide bond (PubMed:2266134, PubMed:4030738). Proteolytically
CC       cleaved by clotting factor G subunit beta (PubMed:7822328).
CC       {ECO:0000269|PubMed:2266134, ECO:0000269|PubMed:4030738,
CC       ECO:0000269|PubMed:7822328}.
CC   -!- PTM: Contains six O-linked carbohydrate chains in the N-terminal light
CC       chain. {ECO:0000269|PubMed:2266134, ECO:0000269|PubMed:4030738}.
CC   -!- SIMILARITY: Belongs to the peptidase S1 family. CLIP subfamily.
CC       {ECO:0000255|PROSITE-ProRule:PRU01236}.
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DR   EMBL; M58366; AAA30094.1; -; mRNA.
DR   PIR; A23689; A23689.
DR   RefSeq; XP_076311529.1; XM_076455414.1.
DR   RefSeq; XP_076311530.1; XM_076455415.1.
DR   RefSeq; XP_076311531.1; XM_076455416.1.
DR   AlphaFoldDB; P21902; -.
DR   SMR; P21902; -.
DR   MEROPS; S01.221; -.
DR   iPTMnet; P21902; -.
DR   GeneID; 143225636; -.
DR   KEGG; ag:AAA30094; -.
DR   GO; GO:0005576; C:extracellular region; EXP:UniProtKB.
DR   GO; GO:0030133; C:transport vesicle; IEA:UniProtKB-SubCell.
DR   GO; GO:0004252; F:serine-type endopeptidase activity; IDA:UniProtKB.
DR   GO; GO:0008236; F:serine-type peptidase activity; IDA:UniProtKB.
DR   GO; GO:0042381; P:hemolymph coagulation; IDA:UniProtKB.
DR   GO; GO:0016485; P:protein processing; IDA:UniProtKB.
DR   CDD; cd00190; Tryp_SPc; 1.
DR   FunFam; 2.40.10.10:FF:000015; Atrial natriuretic peptide-converting enzyme; 1.
DR   Gene3D; 3.30.1640.30; -; 1.
DR   Gene3D; 2.40.10.10; Trypsin-like serine proteases; 1.
DR   InterPro; IPR022700; CLIP.
DR   InterPro; IPR038565; CLIP_sf.
DR   InterPro; IPR009003; Peptidase_S1_PA.
DR   InterPro; IPR001314; Peptidase_S1A.
DR   InterPro; IPR001254; Trypsin_dom.
DR   InterPro; IPR018114; TRYPSIN_HIS.
DR   InterPro; IPR033116; TRYPSIN_SER.
DR   PANTHER; PTHR24252; ACROSIN-RELATED; 1.
DR   PANTHER; PTHR24252:SF7; HYALIN; 1.
DR   Pfam; PF00089; Trypsin; 1.
DR   PRINTS; PR00722; CHYMOTRYPSIN.
DR   SMART; SM00680; CLIP; 1.
DR   SMART; SM00020; Tryp_SPc; 1.
DR   SUPFAM; SSF50494; Trypsin-like serine proteases; 1.
DR   PROSITE; PS51888; CLIP; 1.
DR   PROSITE; PS50240; TRYPSIN_DOM; 1.
DR   PROSITE; PS00134; TRYPSIN_HIS; 1.
DR   PROSITE; PS00135; TRYPSIN_SER; 1.
PE   1: Evidence at protein level;
KW   Calcium; Cleavage on pair of basic residues; Cytoplasmic vesicle;
KW   Direct protein sequencing; Disulfide bond; Glycoprotein;
KW   Hemolymph clotting; Hydrolase; Metal-binding; Protease;
KW   Pyrrolidone carboxylic acid; Secreted; Serine protease; Signal; Zymogen.
FT   SIGNAL          1..21
FT                   /evidence="ECO:0000255"
FT   PROPEP          22..27
FT                   /evidence="ECO:0000305|PubMed:2266134"
FT                   /id="PRO_0000028427"
FT   CHAIN           30..127
FT                   /note="Proclotting enzyme light chain"
FT                   /evidence="ECO:0000305|PubMed:2266134"
FT                   /id="PRO_0000028428"
FT   CHAIN           128..375
FT                   /note="Proclotting enzyme heavy chain"
FT                   /evidence="ECO:0000305|PubMed:2266134"
FT                   /id="PRO_0000028429"
FT   DOMAIN          39..84
FT                   /note="Clip"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01236"
FT   DOMAIN          128..375
FT                   /note="Peptidase S1"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00274"
FT   REGION          90..113
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   ACT_SITE        172
FT                   /note="Charge relay system"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00274"
FT   ACT_SITE        228
FT                   /note="Charge relay system"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00274"
FT   ACT_SITE        326
FT                   /note="Charge relay system"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00274"
FT   BINDING         194
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /evidence="ECO:0000250|UniProtKB:O97366"
FT   BINDING         196
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /evidence="ECO:0000250|UniProtKB:O97366"
FT   BINDING         199
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /evidence="ECO:0000250|UniProtKB:O97366"
FT   BINDING         202
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /evidence="ECO:0000250|UniProtKB:O97366"
FT   SITE            127..128
FT                   /note="Cleavage"
FT                   /evidence="ECO:0000269|PubMed:2266134"
FT   MOD_RES         30
FT                   /note="Pyrrolidone carboxylic acid"
FT                   /evidence="ECO:0000269|PubMed:2266134"
FT   CARBOHYD        122
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000269|PubMed:2266134"
FT   CARBOHYD        235
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000269|PubMed:2266134"
FT   CARBOHYD        304
FT                   /note="N-linked (GlcNAc...) asparagine"
FT                   /evidence="ECO:0000269|PubMed:2266134"
FT   DISULFID        40..83
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01236,
FT                   ECO:0000269|PubMed:2266134"
FT   DISULFID        50..73
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01236,
FT                   ECO:0000269|PubMed:2266134"
FT   DISULFID        56..84
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01236,
FT                   ECO:0000269|PubMed:2266134"
FT   DISULFID        118..248
FT                   /note="Interchain (between light and heavy chains)"
FT                   /evidence="ECO:0000269|PubMed:2266134,
FT                   ECO:0000269|PubMed:4030738"
FT   DISULFID        157..173
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00274,
FT                   ECO:0000269|PubMed:2266134"
FT   DISULFID        295..311
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00274,
FT                   ECO:0000269|PubMed:2266134"
FT   DISULFID        322..351
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00274,
FT                   ECO:0000269|PubMed:2266134"
SQ   SEQUENCE   375 AA;  41592 MW;  94209E514DFCF8FB CRC64;
     MLVNNVFSLL CFPLLMSVVR CSTLSRQRRQ FVFPDEEELC SNRFTEEGTC KNVLDCRILL
     QKNDYNLLKE SICGFEGITP KVCCPKSSHV ISSTQAPPET TTTERPPKQI PPNLPEVCGI
     HNTTTTRIIG GREAPIGAWP WMTAVYIKQG GIRSVQCGGA LVTNRHVITA SHCVVNSAGT
     DVMPADVFSV RLGEHNLYST DDDSNPIDFA VTSVKHHEHF VLATYLNDIA ILTLNDTVTF
     TDRIRPICLP YRKLRYDDLA MRKPFITGWG TTAFNGPSSA VLREVQLPIW EHEACRQAYE
     KDLNITNVYM CAGFADGGKD ACQGDSGGPM MLPVKTGEFY LIGIVSFGKK CALPGFPGVY
     TKVTEFLDWI AEHMV
//