title: Identification and characterization of prokaryotic dipeptidyl-peptidase 5 from Porphyromonas gingivalis.
abstract: Porphyromonas gingivalis, a Gram-negative asaccharolytic anaerobe, is a major causative organism of chronic periodontitis. Because the bacterium utilizes amino acids as energy and carbon sources and incorporates them mainly as dipeptides, a wide variety of dipeptide production processes mediated by dipeptidyl-peptidases (DPPs) should be beneficial for the organism. In the present study, we identified the fourth P. gingivalis enzyme, DPP5. In a dpp4-7-11-disrupted P. gingivalis ATCC 33277, a DPP7-like activity still remained. PGN_0756 possessed an activity indistinguishable from that of the mutant, and was identified as a bacterial orthologue of fungal DPP5, because of its substrate specificity and 28.5% amino acid sequence identity with an Aspergillus fumigatus entity. P. gingivalis DPP5 was composed of 684 amino acids with a molecular mass of 77,453, and existed as a dimer while migrating at 66 kDa on SDS-PAGE. It preferred Ala and hydrophobic residues, had no activity toward Pro at the P1 position, and no preference for hydrophobic P2 residues, showed an optimal pH of 6.7 in the presence of NaCl, demonstrated Km and kcat/Km values for Lys-Ala-MCA of 688 μM and 11.02 μM(-1) s(-1), respectively, and was localized in the periplasm. DPP5 elaborately complemented DPP7 in liberation of dipeptides with hydrophobic P1 residues. Examinations of DPP- and gingipain gene-disrupted mutants indicated that DPP4, DPP5, DPP7, and DPP11 together with Arg- and Lys-gingipains cooperatively liberate most dipeptides from nutrient oligopeptides. This is the first study to report that DPP5 is expressed not only in eukaryotes, but also widely distributed in bacteria and archaea.
authors.affiliation: From the Department of Oral Molecular Biology, Course of Medical and Dental Sciences, and.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Ohara-Nemoto
authors.forename: Shakh M A
authors.initials: SM
authors.lastname: Rouf
authors.forename: Mariko
authors.initials: M
authors.lastname: Naito
authors.forename: Amie
authors.initials: A
authors.lastname: Yanase
authors.forename: Fumi
authors.initials: F
authors.lastname: Tetsuo
authors.forename: Toshio
authors.initials: T
authors.lastname: Ono
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kobayakawa
authors.forename: Yu
authors.initials: Y
authors.lastname: Shimoyama
authors.forename: Shigenobu
authors.initials: S
authors.lastname: Kimura
authors.forename: Koji
authors.initials: K
authors.lastname: Nakayama
authors.forename: Keitarou
authors.initials: K
authors.lastname: Saiki
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Konishi
authors.forename: Takayuki K
authors.initials: TK
authors.lastname: Nemoto
mesh_terms: D001232:Aspergillus fumigatus / Q000201:enzymology / Q000235:genetics; D002384:Catalysis; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D019897:Periplasm / Q000201:enzymology / Q000235:genetics; D033903:Periplasmic Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016966:Porphyromonas gingivalis / Q000201:enzymology / Q000235:genetics; D017386:Sequence Homology, Amino Acid
chemical_list: D005656:Fungal Proteins; D033903:Periplasmic Proteins; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases
keywords: Amino Acid; Metabolism; Peptidases; Periodontal Disease; Subcellular Fractionation