Biosynthesis of Osmoregulated Periplasmic Glucans inEscherichia coli: The Phosphoethanolamine Transferase Is Encoded byopgE

Abstract

Osmoregulated periplasmic glucans (OPGs) are oligosaccharides found in the periplasm of many Gram-negative bacteria. Glucose is the sole constitutive sugar and this backbone may be substituted by various kinds of molecules depending on the species. InE. coli, OPG are substituted by phosphoglycerol and phosphoethanolamine derived from membrane phospholipids and by succinyl residues. In this study, we describe the isolation of theopgEgene encoding the phosphoethanolamine transferase by a screen previously used for the isolation of theopgBgene encoding the phosphoglycerol transferase. Both genes show structural and functional similarities without sequence similarity.