Characterization of the pcp gene encoding the pyrrolidone carboxyl peptidase of Bacillus subtilis

Pyrrolidone carboxyl peptidase (EC 3.4.11.8) (Pcp) is an enzyme that catalyzes the removal of the N-terminal pyroglutamyl group from some peptides or proteins. Its value in protein chemistry and bacterial diagnosis makes this enzyme an interesting subject of study. The present paper reports for the first time the cloning and characterization of a pyrrolidone carboxyl peptidase gene (pcp). This gene is present in a single copy in the genome of Bacillus subtilis as indicated by Southern blot hybridization analysis. The pcp transcripts were analyzed in Escherichia coli by Northern blot hybridization and S1 nuclease mapping. The deduced amino acid sequence predicts a protein of 215 amino acids with a calculated molecular weight of 23,777 Da. The pcp gene has been over-expressed in E. coli, allowing the identification and partial characterization of Pcp protein.