Inducible expression of a Porphyromonas gingivalis W83 membrane-associated protease

The Tpr protease of Porphyromonas gingivalis W83 is a membrane-associated enzyme capable of hydrolyzing a chromogenic bacterial collagenase substrate. An isogenic mutant lacking a functional tpr gene had a greatly reduced ability to hydrolyze the collagenase substrate. Activity was restored to the tpr mutant by introducing a shuttle plasmid containing the tpr gene. Expression of the gene is induced by nutrient limitation, as shown by enzymatic and Northern analyses.