This enzyme is a member of the aromatic amino acid lyase family, other members of which are EC?4.3.1.3?(histidine ammonia-lyase), EC?4.3.1.23?(tyrosine ammonia-lyase) and EC?4.3.1.24?(phenylalanine ammonia-lyase). The enzyme from some monocots, including maize, and from the yeast?Rhodosporidium toruloides, deaminate?L-phenylalanine and?L-tyrosine with similar catalytic efficiency [3]. The enzyme contains the cofactor 3,5-dihydro-5-methylidene-4H-imidazol-4-one (MIO), which is common to this family [3]. This unique cofactor is formed autocatalytically by cyclization and dehydration of the three amino-acid residues alanine, serine and glycine [4].
