ACYL-ACYL CARRIER PROTEIN SPECIFICITY OF UDP-GLCNAC ACYLTRANSFERASES FROM GRAM-NEGATIVE BACTERIA - RELATIONSHIP TO LIPID-A STRUCTURE

Lipid A, the component of lipopolysaccharide that provides the membrane anchor of the core and O-antigen sugars, is known to contain characteristic R-3-hydroxy fatty acids bound to the 2,2' (N-linked) and 3,3' (O-linked) positions of the glucosamine disaccharide in different gram-negative bacteria. The studies reported here show that it is the acyl-acyl carrier protein specificities of the enzymes UDP-GlcNAc-O-acyltransferase and UDP-3-O-[f(R)-3-hydroxyacyl]-GlcN-N-acyltransferase that determine the nature of these fatty acids.