Related Experiment Video
Updated: Aug 6, 2026

Porphyromonas gingivalis as a Model Organism for Assessing Interaction of Anaerobic Bacteria with Host Cells
Published on: December 17, 2015
Outer membrane-associated deoxyribonuclease activity of Porphyromonas gingivalis
A Leduc1, D Grenier, D Mayrand
1Groupe de Recherche en Ecologie Buccale, Faculté de Médecine Dentaire and Département de Biochimie, Faculté des Sciences et de Génie, Université Laval, Ste-Foy, Québec, Canada.
Abstract:
Extracellular outer membrane vesicles which are produced by Gram-negative bacteria may enclose deoxyribonucleic acid (DNA). While characterizing vesicles of Porphyromonas gingivalis, it was found that they do not contain detectable amount of DNA. It was also shown that the presence of deoxyribonuclease activity on whole cells and vesicles can degrade plasmidic and linear DNA. Deoxyribonuclease activity was also demonstrated in several other Gram-negative oral bacterial species. The nuclease activity of P. gingivalis was further characterized. When deoxyribonuclease activity was analyzed by zymography, only one active band was detected under the conditions tested. This nuclease enzyme showed a molecular weight of approximately 50 kDa. The activity was inhibited by 5 mM ZnCl2 or 100 mM EDTA whereas Mg2+ or Ca2+ ions were not required for activity. Activity was totally destroyed by treatment at 70 degrees C for 15 min. Although the enzyme may participate in virulence or provide nucleic acid precursors for bacterial growth, its exact role is still unknown.
Related Concept Videos
Restriction Enzymes
The host bacteria protect their own genomic DNA from these enzymes by methylating these sites. Some...
The Oral Microbiota
Bacterial Phylum Proteobacteria
Other Glycolytic Pathways
Structure of Porins
Bacterial RNA Polymerase
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
