- Glutamate 636 of the Escherichia coli pyruvate dehydrogenase-E1 participates in active center communication and behaves as an engineered acetolactate synthase with unusual stereoselectivity. Nemeria, N., Tittmann, K., Joseph, E., Zhou, L., Vazquez-Coll, M.B., Arjunan, P., Hübner, G., Furey, W., Jordan, F. J. Biol. Chem. (2005)