Acetyltransfer Precedes Uridylyltransfer in the Formation of UDP-N-acetylglucosamine in Separable Active Sites of the Bifunctional GlmU Protein of Escherichia coli †

The GlmU protein is a bifunctional enzyme with both acetyltransferase and uridylyltransferase (pyrophosphorylase) activities which catalyzes the transformation of glucosamine-1-P, UTP, and acetyl-CoA to UDP-N-acetylglucosamine [Mengin-Lecreulx, D., & van Heijenoort, J. (1994) J. Bacteriol. 176, 5788-5795], a fundamental precursor in bacterial peptidoglycan biosynthesis and the source of activated N-acetylglucosamine in lipopolysaccharide …