found in this site, possibly because it would break the helical structure adopted by this motif in metalloproteases. Metallopeptidases from family M48 are integral membrane proteins associated with the endoplasmic reticulum and Golgi, binding one zinc ion per subunit. These endopeptidases include CAAX prenyl protease 1, which proteolytically removes the C-terminal three residues of farnesylated proteins. Metalloproteinase inhibitors are found in numerous marine organisms, including fish, cephalopods, mollusks, algae and bacteria. Members of the M50 metallopeptidase family include: mammalian sterol-regulatory element binding protein (SREBP) site 2 protease and Escherichia coli protease EcfE, stage IV sporulation protein FB. See also Matrix metalloproteinase The Proteolysis Map References External links The MEROPS online database for peptidases and their inhibitors: Metallo Peptidases Proteopedia: Metalloproteases Protein families Proteases