The core lipopolysaccharide (LPS) of Aeromonas hydrophila AH-3 and A. salmonicida A450 is characterized by the presence of the pentasaccharide α-D-GlcN-(1-7)-L-α-D-Hep-(1-2)-L-α-D-Hep-(1-3)-L-α-D-Hep-(1-5)-α-Kdo. Previously it has been suggested that the WahA protein is involved in the incorporation of GlcN residue to outer core lipopolysaccharide (LPS). The WahA protein contains two domains: a glycosyltransferase and a carbohydrate esterase. In this work we demonstrate that the independent expression of the WahA glycosyltransferase domain catalyzes the incorporation of GlcNAc from UDP-GlcNAc to the outer core LPS. Independent expression of the carbohydrate esterase domain leads to the deacetylation of the GlcNAc residue to GlcN. Thus, the WahA is the first described bifunctional glycosyltransfease enzyme involved in the biosynthesis of core LPS. By contrast in Enterobacteriaceae containing GlcN in their outer core LPS the two reactions are performed by two different enzymes
Lipopolysaccharide, biosynthesis, core, glycosyltransferase, Aeromonas hydrophila
NCBI PubMed ID: 19805547Journal NLM ID: 2985121RPublisher: Baltimore, MD: American Society for Biochemistry and Molecular Biology
Correspondence: jtomas@ub.edu
Institutions: Department Microbiologia University Barcelona, Spain
Methods: SDS-PAGE, MALDI-TOF MS, genetic methods, biochemical methods, mild acid degradation
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