N-acylamino acid racemase (NAAAR), an octameric enzyme that catalyzes the racemization of N-acylamino acids. NAAARs act on a broad range of N-acylamino acids rather than amino acids. Enantiopure amino acids are of industrial interest as chiral building blocks for antibiotics, herbicides, and drugs. NAAAR is a member of the enolase superfamily, characterized by the presence of an enolate anion intermediate which is generated by abstraction of the alpha-proton of the carboxylate substrate by an active site residue and is stabilized by coordination to the essential Mg2+ ion.