REVIEW: Common Themes in Glycoconjugate Assembly Using the Biogenesis of O-Antigen Lipopolysaccharide as a Model System*

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M. A. Valvano

Centre for Human Immunology, Department of Microbiology and Immunology and Department of Medicine, University of Western Ontario, London, Ontario N6A 5C1, Canada; fax: +1-519-661-3499; E-mail: mvalvano@uwo.ca

^* This mini-review is based on a presentation made at the 4th Baltic Conference on Microbial Carbohydrates, Hyytiälä Forestry Field Station, Finland, September 19-22, 2010.

Received February 15, 2011; Revision received February 21, 2011

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The biosynthesis of glycoconjugates is remarkably conserved in all types of cells since the biochemical reactions involved exhibit similar characteristics, which can be summarized as follows: (a) the saccharide moiety is formed as a lipid-linked, membrane-associated glycan; (b) the lipid component in most cases is a polyisoprenoid phosphate; (c) the assembly of the lipid-linked saccharide intermediate depends on reactions taking place at both sides of the cell membrane, which requires the obligatory transmembrane movement of amphipathic molecules across the lipid bilayer. These general characteristics are present in the biosynthesis of the O-antigen component of the bacterial lipopolysaccharide, which serves as a model system to investigate the molecular and mechanistic basis of glycoconjugate synthesis, as summarized in this mini-review.

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KEY WORDS: lipopolysaccharide, undecaprenyl phosphate, ligase, glycosylphosphate transferase, outer membrane

DOI: 10.1134/S0006297911070029

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