[Frontiers in Bioscience 8, s452-471, May 1, 2003]

EXPORT OF O-SPECIFIC LIPOPOLYSACCHARIDE

Miguel A. Valvano

Departments of Microbiology and Immunology, and Medicine, University of Western Ontario, London, Ontario N6A 5C1 Canada

TABLE OF CONTENTS

1. Abstract
2. Introduction
3. Biogenesis of O-specific lipopolysaccharides
3.1. Initiation reaction
3.1.1. Polyisoprenyl-phosphate N-acetylhexosamine-1-phosphate transferases
3.1.2. Polyisoprenyl-phosphate hexose-1-phosphate transferases
3.2. Elongation/translocation/polymerization
3.2.1. Wzy/Wzx-dependent pathway
3.2.2. ABC transporter pathway
3.2.3. Synthase pathway
3.3. Ligation reaction
3.4. Recycling of Und-PP
4. Cell surface localization of LPS
5. Areas for future research
6. Acknowledgement
7. References

1. ABSTRACT

The O antigen is the most surface-exposed component of the lipopolysaccharide (LPS) molecule and its biogenesis involves several complex mechanisms not completely well understood. All of these mechanisms involve biochemical reactions that occur on the cytoplasmic side of the plasma membrane as well as several different translocation pathways that deliver the nascent O antigens in a glycolipid form to the periplasmic side of the plasma membrane. This article discusses our current understanding of the mechanisms operating in the biogenesis of the O-specific LPS.