Requires pyridoxal phosphate. The low-specificity?L-threonine aldolase can act on both?L-threonine and?L-allo-threonine [1,2]. The enzyme from?Escherichia coli?can also act on?L-threo-phenylserine and?L-erythro-phenylserine [4]. The enzyme can also catalyse the aldol condensation of glycolaldehyde and glycine to form 4-hydroxy-L-threonine, an intermediate of pyridoxal phosphate biosynthesis [3]. Different from EC?4.1.2.5,?L-threonine aldolase, and EC?4.1.2.49,?L-allo-threonine aldolase.