In enzymology, glutamate racemase (MurI with a capital i) (EC 5.1.1.3) is an enzyme that catalyzes the chemical reaction L-glutamate D-glutamate Hence, this enzyme RacE has one substrate, L-glutamate, and one product, D-glutamate. Glutamate racemase (MurI) serves two distinct metabolic functions: primarily, it is a critical enzyme in cell wall biosynthesis, but also plays a role in gyrase inhibition. The ability of glutamate racemase and other proteins to serve two distinct functions is known as "moonlighting".