Figure 1.

Structure of proMMP-7. (A) Full-length proMMP7 only consists of two domains: a pro-peptide domain (pro) and a catalytic domain (cat), which separates it from the prototype of MMPs. (B) The pro-peptide domain consists of three α-chains and connecting loops. The catalytic domain contains two zinc ions, two copper ions, and a ball-like structure consisting of three α-helices, five β-sheets, and multiple loops [16]. The image was prepared from Protein Data bank entries 2MZE (proMMP-7) using the PyMol (http://www.pymol.org). MMP, matrix metalloproteinase.