The Y265A mutant of alanine racemase (alrY265A) was evaluated as a catalyst for the synthesis of β-hydroxy-α-amino acids. It promotes the PLP-dependent aldol condensation of glycine with a range of aromatic aldehydes. The desired products were obtained with complete stereocontrol at Cα (ee> 99%, D) and moderate to high selectivity at Cβ (up to 97% de). The designed enzyme is thus similar to natural d-threonine aldolases in its substrate ...