title: A pepD-like peptidase from the ruminal bacterium, Prevotella albensis.
abstract: Peptidases of Prevotella spp. play an important role in the breakdown of protein to ammonia in the rumen. This study describes a peptidase cloned from Prevotella albensis M384. DNA from P. albensis was used to complement a peptidase-deficient strain of Escherichia coli, CM107. A cloned fragment, Pep581, which enabled growth of E. coli CM107, contained an ORF of 1452 bp, encoding a 484 amino acid residue protein with a calculated molecular weight of 53.2 kDa and a theoretical pI of 4.90. Pep581 shared similar sequence identity of 47% with PepD from E. coli, and it was also a metallo-aminopeptidase. A putative catalytic metal binding region was identified in Pep581, similar to that found in the related PepT (a tripeptidase) and PepA (an oligopeptidase). Gel filtration indicated Pep581 was a dimer in its native state, similar to PepD of E. coli. PepD is a broad specificity dipeptidase that has been found in several prokaryotes. The enzyme expressed from Pep581 differed from PepD enzymes previously characterised in that it hydrolysed tri- and oligopeptides in addition to dipeptides, cleaving single amino acids from the N terminus.
authors.affiliation: Rowett Research Institute, Bucksburn, Aberdeen AB21 9SB, UK.
authors.forename: Nicola D
authors.initials: ND
authors.lastname: Walker
authors.forename: Neil R
authors.initials: NR
authors.lastname: McEwan
authors.forename: R John
authors.initials: RJ
authors.lastname: Wallace
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004151:Dipeptides / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000378:metabolism; D010447:Peptide Hydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018720:Prevotella / Q000201:enzymology* / Q000235:genetics; D012417:Rumen / Q000382:microbiology*; D016415:Sequence Alignment; D013379:Substrate Specificity
chemical_list: D004151:Dipeptides; D009842:Oligopeptides; D010447:Peptide Hydrolases