Identification and characterization of Lactobacillus helveticus PepO2, an endopeptidase with post-proline specificity.

ABSTRACT: A post-proline endopeptidase (PepO2) was detected in cell extracts from a genomic library of Lactobacillus helveticus CNRZ32 by using the synthetic substrate N-acetyl-beta-casein-(f203-209)-rho-nitroanilide in a coupled reaction with aminopeptidase N. Isolates with activity for this substrate contained plasmids with visually indistinguishable restriction profiles. Nucleotide sequence analysis revealed a 1,947-bp open reading frame, designated pepO2, encoding a putative 71.4-kDa protein. Analysis of the predicted peptide sequence revealed that L. helveticus PepO2 contained the zinc-dependent metalloprotease motif HEXXH and exhibited levels of amino acid sequence similarity of 72, 61, 59, and 53% to L. helveticus PepO, Lactococcus lactis PepO2, L. lactis PepO, and Lactobacillus rhamnosus Pep

SUBMITTER: Chen YS 

PROVIDER: S-EPMC143593 | biostudies-literature | 2003 Feb

REPOSITORIES: biostudies-literature