<p>This domain is found in many tryptophanases (tryptophan indole-lyase, TNase), tyrosine phenol-lyases (TPL) and threonine aldolases. It is involved in the degradation of amino acids. The glycine cleavage system is composed of four proteins: P, T, L and H. In <taxon tax_id="1423">Bacillus subtilis</taxon>, the P 'protein' is an heterodimer of two subunits. The glycine cleavage system catalyses the degradation of glycine. The P protein binds the alpha-amino group of glycine through its pyridoxal phosphate cofactor; CO(2) is released and the remaining methylamine moiety is then transferred to the lipoamide cofactor of the H protein</p> Aromatic amino acid beta-eliminating lyase/threonine aldolase