Fig. 2.

Structures of MMPs, M9A, and M9B. (A) Signal peptides direct the MMP to the secretory pathway or the plasma membrane insertion pathway. The propeptide maintains the stability of the proenzyme, and when this region is removed by exogenous enzymes, the MMP proenzyme is activated. The zinc-containing catalytic active region dominates enzyme-mediated catalysis, and the hinge region connects the catalytic and hemoglobin domains. (B) Domain structures of collagenase from Vibrio parahaemolyticus. (C) Domain structures of collagenase from Vibrio alginolyticus. (D) Domain structures of collagenase from Vibrio mimicus. (E and F) Domain structures of collagenases from C. histolyticum (ColG and ColH).