ID   TRYP_SQUAC              Reviewed;         229 AA.
AC   P00764;
DT   21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT   21-JUL-1986, sequence version 1.
DT   02-SEP-2026, entry version 111.
DE   RecName: Full=Trypsin;
DE            EC=3.4.21.4;
DE   Flags: Precursor;
OS   Squalus acanthias (Spiny dogfish).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Chondrichthyes;
OC   Elasmobranchii; Squalomorphii; Squaliformes; Squalidae; Squalus.
OX   NCBI_TaxID=7797;
RN   [1]
RP   PROTEIN SEQUENCE OF 8-229.
RX   PubMed=1092332; DOI=10.1021/bi00678a003;
RA   Titani K., Ericsson L.H., Neurath H., Walsh K.A.;
RT   "Amino acid sequence of dogfish trypsin.";
RL   Biochemistry 14:1358-1366(1975).
RN   [2]
RP   PROTEIN SEQUENCE OF 1-21.
RX   PubMed=11945763; DOI=10.1016/0014-5793(71)80622-1;
RA   Hermodson M.A., Tye R.W., Reeck G.R., Neurath H., Walsh K.A.;
RT   "Comparison of the amino terminal sequences of bovine, dogfish, and
RT   lungfish trypsinogens.";
RL   FEBS Lett. 14:222-224(1971).
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Preferential cleavage: Arg-|-Xaa, Lys-|-Xaa.; EC=3.4.21.4;
CC   -!- COFACTOR:
CC       Name=Ca(2+); Xref=ChEBI:CHEBI:29108; Evidence={ECO:0000250};
CC       Note=Binds 1 Ca(2+) ion per subunit. {ECO:0000250};
CC   -!- SUBCELLULAR LOCATION: Secreted, extracellular space.
CC   -!- SIMILARITY: Belongs to the peptidase S1 family. {ECO:0000255|PROSITE-
CC       ProRule:PRU00274}.
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DR   PIR; A00950; TRDFS.
DR   SMR; P00764; -.
DR   CDD; cd00190; Tryp_SPc; 1.
DR   FunFam; 2.40.10.10:FF:000008; Cationic trypsin; 1.
DR   FunFam; 2.40.10.10:FF:000005; Serine protease 37; 1.
DR   Gene3D; 2.40.10.10; Trypsin-like serine proteases; 2.
DR   InterPro; IPR009003; Peptidase_S1_PA.
DR   InterPro; IPR001314; Peptidase_S1A.
DR   InterPro; IPR050127; Serine_Proteases_S1.
DR   InterPro; IPR001254; Trypsin_dom.
DR   InterPro; IPR018114; TRYPSIN_HIS.
DR   InterPro; IPR033116; TRYPSIN_SER.
DR   PANTHER; PTHR24264:SF15; RIKEN CDNA 2210010C04 GENE; 1.
DR   PANTHER; PTHR24264; TRYPSIN-RELATED; 1.
DR   Pfam; PF00089; Trypsin; 1.
DR   PRINTS; PR00722; CHYMOTRYPSIN.
DR   SMART; SM00020; Tryp_SPc; 1.
DR   SUPFAM; SSF50494; Trypsin-like serine proteases; 1.
DR   PROSITE; PS50240; TRYPSIN_DOM; 1.
DR   PROSITE; PS00134; TRYPSIN_HIS; 1.
DR   PROSITE; PS00135; TRYPSIN_SER; 1.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0004252; F:serine-type endopeptidase activity; IEA:UniProtKB-EC.
DR   GO; GO:0006508; P:proteolysis; IEA:InterPro.
DR   AlphaFoldDB; P00764; -.
PE   1: Evidence at protein level;
KW   Calcium; Digestion; Direct protein sequencing; Disulfide bond; Hydrolase;
KW   Metal-binding; Protease; Secreted; Serine protease; Zymogen.
FT   PROPEP          1..7
FT                   /note="Activation peptide"
FT                   /evidence="ECO:0000269|PubMed:1092332"
FT                   /id="PRO_0000028231"
FT   CHAIN           8..229
FT                   /note="Trypsin"
FT                   /id="PRO_0000028232"
FT   DOMAIN          8..227
FT                   /note="Peptidase S1"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00274"
FT   ACT_SITE        47
FT                   /note="Charge relay system"
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        91
FT                   /note="Charge relay system"
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        183
FT                   /note="Charge relay system"
FT                   /evidence="ECO:0000250"
FT   BINDING         59
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /evidence="ECO:0000250"
FT   BINDING         69
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /evidence="ECO:0000250"
FT   SITE            177
FT                   /note="Required for specificity"
FT                   /evidence="ECO:0000250"
FT   DISULFID        14..143
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00274"
FT   DISULFID        32..48
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00274"
FT   DISULFID        116..216
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00274"
FT   DISULFID        123..189
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00274"
FT   DISULFID        154..168
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00274"
FT   DISULFID        179..203
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00274"
FT   VARIANT         109
FT                   /note="L -> P"
SQ   SEQUENCE   229 AA;  24591 MW;  E83B83C5AD72FCE4 CRC64;
     APDDDDKIVG GYECPKHAAP WTVSLNVGYH FCGGSLIAPG WVVSAAHCYQ RRIQVRLGEH
     DISANEGDET YIDSSMVIRH PNYSGYDLDN DIMLIKLSKP AALNRNVDLI SLPTGCAYAG
     EMCLISGWGN TMDGAVSGDQ LQCLDAPVLS DAECKGAYPG MITNNMMCVG YMEGGKDSCQ
     GDSGGPVVCN GMLQGIVSWG YGCAERDHPG VYTRVCHYVS WIHETIASV
//