title: Fatty acyl derivatives of glucosamine 1-phosphate in Escherichia coli and their relation to lipid A. Complete structure of A diacyl GlcN-1-P found in a phosphatidylglycerol-deficient mutant.
abstract: We have determined the complete structure of a glycolipid (designated lipid X) previously found to accumulate in certain Escherichia coli mutants defective in phosphatidylglycerol synthesis (Nishijima, M., and Raetz, C.R.H. (1979) J. Biol. Chem. 254, 7837-7844). Based on fast atom bombardment mass spectrometry and proton nuclear magnetic resonance studies, this substance is an acylated metabolite of glucosamine 1-phosphate. Lipid X of E. coli has a Mr = 711.87 as the free acid (C34H66NO12P) and contains two beta-hydroxymyristate moieties, one attached as an amide at the 2 position and the other as an ester at the 3 position of the sugar. It has free hydroxyl groups at the 4 and 6 positions, and the anomeric configuration is alpha. The structure of lipid X from E. coli closely resembles the reducing end subunit of lipid A, and it might represent a very early precursor in the biosynthesis of lipid A. To our knowledge, fatty acyl derivatives of glucosamine 1-phosphate have not been reported previously.
mesh_terms: D004926:Escherichia coli / Q000378:metabolism*; D005227:Fatty Acids / Q000096:biosynthesis / Q000302:isolation & purification; D005944:Glucosamine / Q000031:analogs & derivatives* / Q000378:metabolism; D005958:Glucosephosphates; D008050:Lipid A / Q000096:biosynthesis*; D008070:Lipopolysaccharides / Q000096:biosynthesis* / Q000302:isolation & purification; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D009154:Mutation; D010715:Phosphatidylglycerols / Q000378:metabolism*
chemical_list: D005227:Fatty Acids; D005958:Glucosephosphates; D008050:Lipid A; D008070:Lipopolysaccharides; D010715:Phosphatidylglycerols; C038515:glucosamine 1-phosphate; D005944:Glucosamine