Metzincin is a superfamily of metalloproteases, so-called because of a conserved methionine C-terminal to the zinc ligands that forms what is known as a "Met-turn". They orchestrate the growth and remodeling of tissues and the responses of cells to their extracellular environment. They are zinc-dependent and contain three histidine residues at the catalytic site. In addition, the conserved methionine provides a base for the zinc-binding site. (Adapted from FBrf0219187 and PMID:19374923).