Figure 2.

Structure of MMP-13. MMP-13 typically consists of a highly conserved signal peptide, a propeptide domain, a catalytic domain, a proline-rich hinge region, and a C-terminal hemopexin-like domain. The catalytic domain of MMP-13 is represented by the crystal structure. The structural zinc ion is in green, the catalytic zinc ion is in magenta, and three calcium ions are in dark grey. Three histidine residues in black sticks coordinate the catalytic zinc ion. The highly flexible S1′ specificity loop as part of hydrophobic S1′ pocket is a determining factor for the selective inhibitors of MMP-13. Created with BioRender.com.