Members of the ICL/PEPM enzyme family catalyze either P-C or C-C bond formation/cleavage. Known members are phosphoenolpyruvate mutase (PEPM), phosphonopyruvate hydrolase (PPH), carboxyPEP mutase (CPEP mutase), oxaloacetate hydrolase (OAH), isocitrate lyase (ICL), and 2-methylisocitrate lyase (MICL). Isocitrate lyase (ICL) catalyzes the conversion of isocitrate to succinate and glyoxylate, the first committed step in the glyoxylate pathway. This carbon-conserving pathway is present in most prokaryotes, lower eukaryotes and plants, but has not been observed in vertebrates. PEP mutase (PEPM) turns phosphoenolpyruvate (PEP) into phosphonopyruvate (P-pyr), an important intermediate in the formation of organophosphonates, which function as antibiotics or play a role in pathogenesis or signaling. P-pyr can be hydrolyzed by phosphonopyruvate hydrolase (PPH) to from pyruvate and phosphate. Oxaloacetate acetylhydrolase (OAH) catalyzes the hydrolytic cleavage of oxaloacetate to form acetate and oxalate, an important pathway to produce oxalate in filamentous fungi. 2-methylisocitrate lyase (MICL) cleaves 2-methylisocitrate to pyruvate and succinate, part of the methylcitrate cycle for the alpha-oxidation of propionate.