MMPs typically consist of several structural domains: 1. A pro-domain, which maintains the enzyme in an inactive form. 2. A catalytic domain, containing the zinc ion essential for enzymatic activity. 3. A hemopexin-like domain, which is involved in substrate specificity and interaction with tissue inhibitors of metalloproteinases (TIMPs). Some MMPs also have a fibronectin-like domain that enhances binding to gelatin and collagen.
