Matrix metalloproteinases (MMPs) are highly homologous Zn2+ endopeptidases involved in extracellular matrix breakdown. MMP mediated extracellular remodeling occurs in normal physiological processes, such as embryonic development, reproduction and tissue remodeling, and disease processes, including arthritis and metastasis. MMP-23 exhibits sequence similarity with most MMPs, but displays a difference in domain structure. The MMP-23 protein contains prepro-, catalytic, cysteine-rich, Interleukin-1 receptor-related and proline-rich domains. Lacking a recognizable signal sequence, MMP-23 has a short prodomain. In addition, MMP-23 contains a single cysteine residue that can be part of the cysteine-switch mechanism operation for maintaining enzyme latency. MMP-23 is a membrane-anchored glycoprotein with type II topology. Subcellular localization is predominantly perinuclear.