title: Asp- and Glu-specific novel dipeptidyl peptidase 11 of Porphyromonas gingivalis ensures utilization of proteinaceous energy sources.
abstract: Porphyromonas gingivalis and Porphyromonas endodontalis, asaccharolytic black-pigmented anaerobes, are predominant pathogens of human chronic and periapical periodontitis, respectively. They incorporate di- and tripeptides from the environment as carbon and energy sources. In the present study we cloned a novel dipeptidyl peptidase (DPP) gene of P. endodontalis ATCC 35406, designated as DPP11. The DPP11 gene encoded 717 amino acids with a molecular mass of 81,090 Da and was present as a 75-kDa form with an N terminus of Asp(22). A homology search revealed the presence of a P. gingivalis orthologue, PGN0607, that has been categorized as an isoform of authentic DPP7. P. gingivalis DPP11 was exclusively cell-associated as a truncated 60-kDa form, and the gene ablation retarded cell growth. DPP11 specifically removed dipeptides from oligopeptides with the penultimate N-terminal Asp and Glu and has a P2-position preference to hydrophobic residues. Optimum pH was 7.0, and the k(cat)/K(m) value was higher for Asp than Glu. Those activities were lost by substitution of Ser(652) in P. endodontalis and Ser(655) in P. gingivalis DPP11 to Ala, and they were consistently decreased with increasing NaCl concentration. Arg(670) is a unique amino acid completely conserved in all DPP11 members distributed in the genera Porphyromonas, Bacteroides, and Parabacteroides, whereas this residue is converted to Gly in all authentic DPP7 members. Substitution analysis suggested that Arg(670) interacts with an acidic residue of the substrate. Considered to preferentially utilize acidic amino acids, DPP11 ensures efficient degradation of oligopeptide substrates in these Gram-negative anaerobic rods.
authors: Department of Oral Molecular Biology, Course of Medical and Dental Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8588. Electronic address: ynemoto@nagasaki-u.ac.jp.
authors: Yuko
authors: Y
authors: Ohara-Nemoto
authors: Division of Molecular Microbiology, Department of Microbiology, Iwate Medical University, Yahaba-cho 028-3691, Japan.
authors: Yu
authors: Y
authors: Shimoyama
authors: Division of Molecular Microbiology, Department of Microbiology, Iwate Medical University, Yahaba-cho 028-3691, Japan.
authors: Shigenobu
authors: S
authors: Kimura
authors: Division of Molecular Microbiology, Department of Microbiology, Iwate Medical University, Yahaba-cho 028-3691, Japan.
authors: Asako
authors: A
authors: Kon
authors: Division of Molecular Microbiology, Department of Microbiology, Iwate Medical University, Yahaba-cho 028-3691, Japan.
authors: Hiroshi
authors: H
authors: Haraga
authors: Department of Oral Molecular Biology, Course of Medical and Dental Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8588.
authors: Toshio
authors: T
authors: Ono
authors: Department of Oral Molecular Biology, Course of Medical and Dental Sciences, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki 852-8588.
authors: Takayuki K
authors: TK
authors: Nemoto
mesh_terms: D000595:Amino Acid Sequence; D001224:Aspartic Acid / Q000737:chemistry*; D001483:Base Sequence; D003001:Cloning, Molecular; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Q000737:chemistry / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D018698:Glutamic Acid / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D016966:Porphyromonas gingivalis / Q000201:enzymology*; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry; D017386:Sequence Homology, Amino Acid
chemical_list: D011506:Proteins; D011994:Recombinant Proteins; D001224:Aspartic Acid; D018698:Glutamic Acid; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases