Calcium regulates the activity and structural stability of TPR, a bacterial calpain-like peptidase

Abstract

Background: Calcium-activated, family C2 cysteine peptidases (calpains) are rare among prokaryotes, and none have been characterized. Results: Tpr peptidase from Porphyromonas gingivalis requires calcium for stability, autoprocessing, and activity. Conclusion: Tpr is the calcium-regulated peptidase well adapted to function on the P. gingivalis cell surface. Significance: Tpr is the first characterized bacteria-derived calpain-like peptidase.