The major pathway for the catabolism of glycine involves the oxidative cleavage of glycine to CO2, NH4+ and a methylene group, which is accepted by tetrahydrofolate in a reversible reaction catalyzed by the glycine cleavage system/complex (GCC). In animals and plants, the GCC is composed of four proteins (three enzymes and a carrier protein) that form a complex loosely associated with the mitochondrial inner membrane. The enzymes are: i) P-protein or glycine dehydrogenase (decarboxylating), ii) T-protein or aminomethyl-transferase, and iii) L-protein or dihydrolipoamide dehydrogenase. The carrier protein is called H-protein (a lipoic acid-containing protein). (Adapted from
PMID:18941301.)
