Molecular genetics and biochemistry of Yersinia lipopolysaccharide

Studies on the molecular genetics of bacterial LPS' serve at least two main purposes: (i) to help develop an understanding of the biology, biochemistry and genetics of this bacterial surface macromolecule, and (ii) to provide a basis for both vaccine development and virulence experiments. Both of these goals have been the driving force in studies of Yersinia LPS carried out during the last decade. Here we will review the progress made in the molecular genetics and biochemistry of Yersinia LPS. A deep understanding has been achieved with respect to Y. enterocolitica serotype O:3, reaching as far as a detailed analysis of the gene clusters directing the biosynthesis of the outer core oligosaccharide and of the O-ag(2). The O-ag gene clusters of Y. enterocolitica serotype O:8 and Y, pseudotuberculosis serotypes O:2a and O:5a have also been cloned and partially characterized. LPS biosynthesis of these Yersinia species includes examples of the two major variations recognized in the biosynthesis of this macromolecule: (i) homopolymeric or O-antigen polymerase-independent biosynthesis, and (ii) heteropolymeric or O-antigen polymerase-dependent biosynthesis.