title: Molecular cloning and nucleotide sequence of cDNA coding for calf preprochymosin.
abstract: DNA complementary to calf stomach mRNA has been synthesised and inserted into the Pst1 site of pAT153 by G-C tailing. Clones containing sequences coding for prochymosin were recognised by colony hybridisation with cDNA extended from a chemically synthesised oligodeoxynucleotide primer, the sequence of which was predicted from the published amino acid sequence of calf prochymosin. Two clones were identified which together contained a complete copy of prochymosin mRNA. The nucleotide sequence is in substantial agreement with the reported amino acid sequence of prochymosin and shows that this protein has a mol.wt. of 40431 and chymosin a mol.wt. of 35612. The sequence also indicates that prochymosin is synthesised as a precursor molecule, preprochymosin, having a 16 amino acid hydrophobic leader sequence analogous to that reported for other secreted proteins.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002417:Cattle; D012085:Chymosin / Q000235:genetics*; D003001:Cloning, Molecular; D004247:DNA; D004262:DNA Restriction Enzymes; D004792:Enzyme Precursors / Q000235:genetics*; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics; D013270:Stomach / Q000201:enzymology
chemical_list: D004792:Enzyme Precursors; D012333:RNA, Messenger; D004247:DNA; D004262:DNA Restriction Enzymes; C034675:preprorennin; D012085:Chymosin