[Regulation of the O-antigen polysaccharide chain length by Wzz- a review ].

The O-antigen of Gram-negative bacterium plays an important role in the signal identification, adhesion, immune evasion and other processes. There are three O-antigen polysaccharides biosynthesis mechanisms according to the type of the flippase that is involved. The Wzy-dependent mechanism is more commonly seen. In Wzy-dependent mechanism, the wzz gene is involved in regulating the length of O-antigen polysaccharide chain which can affect antigenicity of the pathogen and immune response of the host. Based on the crystal structure of Wzz (regulator of the O- antigen polysaccharides length) , different length of O-antigen chain can be obtained through molecular modification of the gene wzz. Conjugating O-antigen or its mutants of a pathogen to a carrier protein could help to develop a vaccine that have both a good target specificity and a strong immunogenicity. Therefore, it is important to understand the function, structure and mechanism of Wzz for the development and production of glycoconjugates vaccine.