AMT (Aminomethyltransferase), also known as GCST (Glycine cleavage system T), GCE or NKH, is a 403 amino acid mitochondrial protein that is one of four components of the glycine cleavage system. The glycine cleavage system is comprised of AMT (known as Protein T), GCSH (known as Protein H), DLD (known as Protein L) and GLDC (known as Protein P), all of which work together to catalyze the cleavage and degradation of glycine. Expressed ubiquitously, AMT plays a crucial role in glycine degradation pathway, specifically catalyzing the creation of 5,10-methylenetetrahydrofolate.