The morbidity of periodontal disease is reported to be 50% above in population worldwide. Some Non-Fermenting Gram-Negative Rods (NFGNR), such as Porphyromonas gingivalis, may cause periodontal disease. NFGNR is well known for utilizing peptides or proteins as energy and carbon sources instead of carbohydrates. DPPs(Dipeptidyl aminopeptidase) are peptide degradation enzymes that play a key part in the absorption of peptides. Bacterial DPPs are divided into two families(Clan SC S9, Clan PA S46). Interestingly, DPPs of Clan PA S46 are only found in bacteria. Our crystallographic studies of Pseudoxanthomonas mexicana WO24 DAP BII and P. gingivalis DPP11 revealed the catalytic and substrate recognition mechanisms of the S46 peptidases.
