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Porphyromonas gingivalis DPP-7 represents a novel type of dipeptidylpeptidase
1Department of Biochemistry and Molecular Biology, University of Georgia, Athens, Georgia 30602, USA.
Abstract:
A novel dipeptidylpeptidase (DPP-7) was purified from the membrane fraction of Porphyromonas gingivalis. This enzyme, with an apparent molecular mass of 76 kDa, has the specificity for both aliphatic and aromatic residues in the P1 position. Although it belongs to the serine class of peptidases, it does not resemble other known dipeptidylpeptidases. Interestingly, the amino acid sequence around the putative active site serine residue shows significant similarity to the C-terminal region of the Staphylococcus aureus V-8 endopeptidase. The genes encoding homologues of DPP-7 were found in genomes of Xylella fastidiosa, Shewanella putrefaciens, and P. gingivalis. It is likely that at least in P. gingivalis, DPP-7 and its homologue, in concert with other di- and tripeptidases, serve nutritional functions by providing dipeptides to this asaccharolytic bacterium.
Insights
Researchers discovered a novel serine peptidase, dipeptidylpeptidase 7 (DPP-7), in Porphyromonas gingivalis. This enzyme provides dipeptides for nutrition, aiding this asaccharolytic bacterium.
Area of Science:
- Microbiology
- Enzymology
- Biochemistry
Background:
- Porphyromonas gingivalis is an asaccharolytic bacterium requiring external nutrient sources.
- Dipeptidylpeptidases play a role in protein degradation and nutrient acquisition.
Purpose of the Study:
- To identify and characterize novel peptidases in Porphyromonas gingivalis.
- To elucidate the functional role of dipeptidylpeptidase 7 (DPP-7) in bacterial nutrition.
Main Methods:
- Purification of DPP-7 from P. gingivalis membrane fractions.
- Enzyme activity assays to determine substrate specificity.
- Bioinformatic analysis of DPP-7 gene homologues in other bacterial genomes.
Main Results:
- A novel 76 kDa serine peptidase, DPP-7, was purified from P. gingivalis.
- DPP-7 exhibits specificity for aliphatic and aromatic residues at the P1 position.
- DPP-7 shares sequence similarity with Staphylococcus aureus V-8 endopeptidase active site.
- Homologous genes were identified in Xylella fastidiosa, Shewanella putrefaciens, and P. gingivalis.
Conclusions:
- DPP-7 represents a novel class of dipeptidylpeptidases.
- DPP-7 likely contributes to the nutritional requirements of P. gingivalis by generating dipeptides.
- DPP-7 and its homologues may have conserved roles in bacterial metabolism.