ID   CHYM_SHEEP              Reviewed;         381 AA.
AC   P18276;
DT   01-NOV-1990, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1990, sequence version 1.
DT   03-AUG-2022, entry version 114.
DE   RecName: Full=Chymosin;
DE            EC=3.4.23.4;
DE   AltName: Full=Preprorennin;
DE   Flags: Precursor;
GN   Name=CYM;
OS   Ovis aries (Sheep).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC   Eutheria; Laurasiatheria; Artiodactyla; Ruminantia; Pecora; Bovidae;
OC   Caprinae; Ovis.
OX   NCBI_TaxID=9940;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RX   PubMed=2117748; DOI=10.1093/nar/18.15.4602;
RA   Pungecar J., Strukelj B., Gubensek F., Turk V., Kregar I.;
RT   "Complete primary structure of lamb preprochymosin deduced from cDNA.";
RL   Nucleic Acids Res. 18:4602-4602(1990).
CC   -!- FUNCTION: Chymosin is synthesized in the mucosa of the stomach. The
CC       enzyme hydrolyzes casein to paracasein.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Broad specificity similar to that of pepsin A. Clots milk by
CC         cleavage of a single 104-Ser-Phe-|-Met-Ala-107 bond in kappa-chain of
CC         casein.; EC=3.4.23.4;
CC   -!- SUBUNIT: Monomer.
CC   -!- SIMILARITY: Belongs to the peptidase A1 family. {ECO:0000305}.
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DR   EMBL; X53037; CAA37209.1; -; mRNA.
DR   PIR; S10996; CMSHB.
DR   RefSeq; NP_001009804.1; NM_001009804.1.
DR   AlphaFoldDB; P18276; -.
DR   SMR; P18276; -.
DR   STRING; 9940.ENSOARP00000020902; -.
DR   MEROPS; A01.006; -.
DR   GeneID; 443399; -.
DR   KEGG; oas:443399; -.
DR   CTD; 229697; -.
DR   eggNOG; KOG1339; Eukaryota.
DR   OrthoDB; 1619495at2759; -.
DR   Proteomes; UP000002356; Unplaced.
DR   GO; GO:0004190; F:aspartic-type endopeptidase activity; IEA:UniProtKB-KW.
DR   GO; GO:0007586; P:digestion; IEA:UniProtKB-KW.
DR   GO; GO:0006508; P:proteolysis; IEA:UniProtKB-KW.
DR   CDD; cd05478; pepsin_A; 1.
DR   Gene3D; 2.40.70.10; -; 2.
DR   InterPro; IPR001461; Aspartic_peptidase_A1.
DR   InterPro; IPR001969; Aspartic_peptidase_AS.
DR   InterPro; IPR012848; Aspartic_peptidase_N.
DR   InterPro; IPR034162; Pepsin_A.
DR   InterPro; IPR033121; PEPTIDASE_A1.
DR   InterPro; IPR021109; Peptidase_aspartic_dom_sf.
DR   PANTHER; PTHR47966; PTHR47966; 1.
DR   Pfam; PF07966; A1_Propeptide; 1.
DR   Pfam; PF00026; Asp; 1.
DR   PRINTS; PR00792; PEPSIN.
DR   SUPFAM; SSF50630; SSF50630; 1.
DR   PROSITE; PS00141; ASP_PROTEASE; 2.
DR   PROSITE; PS51767; PEPTIDASE_A1; 1.
PE   2: Evidence at transcript level;
KW   Aspartyl protease; Digestion; Disulfide bond; Hydrolase; Protease;
KW   Reference proteome; Signal; Zymogen.
FT   SIGNAL          1..16
FT   PROPEP          17..58
FT                   /note="Activation peptide"
FT                   /id="PRO_0000025994"
FT   CHAIN           59..381
FT                   /note="Chymosin"
FT                   /id="PRO_0000025995"
FT   DOMAIN          74..378
FT                   /note="Peptidase A1"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01103"
FT   ACT_SITE        92
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU10094"
FT   ACT_SITE        274
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU10094"
FT   DISULFID        105..110
FT                   /evidence="ECO:0000250"
FT   DISULFID        265..269
FT                   /evidence="ECO:0000250"
FT   DISULFID        308..341
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   381 AA;  42075 MW;  D9903528FA071C47 CRC64;
     MRCLVVLLAV FALSQGAEIT RIPLYKGKPL RKALKERGLL EDFLQKQQYG VSSEYSGFGE
     VASVPLTNYL DSQYFGKIYL GTPPQEFTVL FDTGSSDFWV PSIYCKSNAC KNHQRFDPRK
     SSTFQNLGKP LSIRYGTGSM QGILGYDTVT VSNIVDIQQT VGLSTQEPGD VFTYAEFDGI
     LGMAYPSLAS EYSVPVFDNM MDRRLVAQDL FSVYMDRSGQ GSMLTLGAID PSYYTGSLHW
     VPVTLQKYWQ FTVDSVTISG AVVACEGGCQ AILDTGTSKL VGPSSDILNI QQAIGATQNQ
     YGEFDIDCDS LSSMPTVVFE INGKMYPLTP YAYTSQEEGF CTSGFQGENH SHQWILGDVF
     IREYYSVFDR ANNLVGLAKA I