M79 metalloendopeptidases belong to MEROPS family M79. This family contains specialised endopeptidases that typically cleave a C-terminal tripeptide from an isoprenylated protein, and are termed prenyl proteases (family II). The specificity of the prenyl-processing peptidases is usually described as cleavage of the '-CaaX' motif, a representation of the C-terminal tetrapeptide of the substrate protein. (Note that peptidases in family M48, prenyl-protease family I, catalyse a similar reaction to those in family M79 - the specificities are overlapping but are not identical.) (Adapted from FBrf0239469.)