||Keywords: lipopolysaccharide; glycosyltransferase; Kdo; Burkholderia cepacia; structural analysis |
In this project we are working on the biosynthesis of the lipopolysaccharide (LPS) core region of Burkholderia cepacia and Acinetobacter haemolyticus. Both microorganisms contain the unusual sugar D-glycero-D-talo-oct-2-ulosonic acid (Ko) in addition to the conserved sugar 3-deoxy-D-manno-oct-2-ulosonic acid (Kdo). Our results indicate that Ko is not incorporated by a specific Ko transferase but is generated from Kdo by the action of a so far unknown enzyme. This enzyme, a putative Kdo hydroxylase, is assumed to introduce a hydroxyl function into the sugar ring of Kdo. Using different approaches we want to clone the responsible gene and express the encoded protein to examine its function in vitro as well as in vivo. In this context different LPS mutants will be generated and their biological and chemical properties analysed in order to elucidate the role of Ko in the LPS of bacteria.