Cloning and DNA sequence analysis of pepQ, a prolidase gene from Lactobacillus delbrueckii subsp. lactis DSM7290 and partial characterization of its product

Mol Gen Genet. 1995 May 20;247(4):494-500. doi: 10.1007/BF00293152.


From a genomic library of Lactobacillus delbrueckii subsp. lactis (DSM7290) DNA, in the low-copy-number vector pLG339, a recombinant clone was selected, which complemented a mutation in the prolidase gene (pepQ) of Escherichia coli UK173. Nucleotide sequence analysis revealed an open reading frame of 1104 nucleotides corresponding to a protein of 368 amino acids with a calculated pI of 4.64 and a molecular mass of 41,087 Da. The start site of pepQ transcription was determined by primer extension analysis with mRNA prepared from L. delbrueckii. Based on homology of the gene product to various peptidases and on the substrate specificity determined, the peptidase was designated PepQ. The influence of various protease inhibitors and cations on peptidase activity indicated that PepQ is a metalloprotease. The absence of a membrane-spanning domain and a signal peptide sequence argues for a cytoplasmic localization of the enzyme.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Cloning, Molecular
  • Dipeptidases / genetics*
  • Dipeptidases / metabolism
  • Genes, Bacterial*
  • Lactobacillus / genetics*
  • Metalloendopeptidases / genetics
  • Molecular Sequence Data
  • Phylogeny
  • Promoter Regions, Genetic
  • Recombinant Proteins / metabolism
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Substrate Specificity


  • Recombinant Proteins
  • Dipeptidases
  • proline dipeptidase
  • Metalloendopeptidases

Associated data

  • GENBANK/Z54205