Escherichia coli prlC Gene Encodes a Trypsin-Like Proteinase Regulating the Cell Cycle

• Published in: Journal of biochemistry (Tokyo) 1998-11, Vol.124 (5), p.980-985
• Main Authors: Jiang, Xueyuan, Zhang, Minyue, Ding, Yi, Yao, Jun, Chen, Hao, Zhu, Dexu, Muramatu, Mutumi
• Format: Article
• Language: English
• Subjects: 4-Guanidino benzoic acid 4-tert-butylphenyl ester; antipain; Base Sequence; cell cycle; Cell Cycle Proteins - genetics; Cloning, Molecular; DNA Primers; Electrophoresis, Polyacrylamide Gel; Endopeptidases - genetics; Endopeptidases - isolation & purification; Endopeptidases - metabolism; Escherichia coli; Escherichia coli - genetics; Escherichia coli Proteins; gene expression; Genes, Bacterial; oligopeptidase A; prlC; prlC gene; proteinase In; Recombinant Proteins - genetics; Recombinant Proteins - isolation & purification; Recombinant Proteins - metabolism; Serine Endopeptidases - genetics; Serine Endopeptidases - isolation & purification; Serine Endopeptidases - metabolism; Substrate Specificity; trypsin-like proteinase
• ISSN: 0021-924X
• DOI: 10.1093/oxfordjournals.jbchem.a022216

Proteinase In has previously been described as displaying a trypsin-like proteinase activity that momentarily appears immediately before DNA synthesis in the cell cycle of Escherichia coli synchronized by phosphate starvation and which is closely related to the initiation of DNA replication [Kato, M., Irisawa, T., Ohtani, M., and Muramatu, M. (1992) Eur. J. Biochem. 210, 1007–1014]. We purified the proteinase In from E. coli C600 and found that the 15 amino acid residues of its amino-terminal were identical with those of oligopeptidase A (OpdA), the product of the E. coli prIC gene. The purified proteinase had a molecular mass of approximately 67 kDa, which was also the same as that of oligopeptidase A. To further elucidate the relationship between proteinase in and oligopeptidase A, we assembled an expression vector to direct the synthesis of E. coli oligopeptidase A. The protein was expressed at a high level in E. coli BL21(DE3) and was produced mostly in the soluble, active form. Both the recombinant enzyme (rPrlC) and the purified proteinase In could hydrolyze trypsin substrates for proteinase In as well as benzyloxycarbonyl AlaAla-Leu p-nitroanilide (Z-AALpNA), described as a synthetic substrate for oligopeptidase A. The effects of various protease inhibitors on rPrlC were also very similar to those on proteinase in. The trypsin inhibitors 4-guanidino benzoic acid 4-tert-butylphenyl ester and antipain strongly inhibited the trypsin-like proteinase activity of the recombinant enzyme, but had no effect on its Z-AALpNA hydrolyzing activity. Cobalt ion, which greatly enhanced the OpdA activity, slightly inhibited the trypsin-like activity of the recombinant enzyme. These results strongly suggest that proteinase in is encoded by the E. coli prlC gene and is a multi-functional proteinase with two separate active sites.