title: Membrane Translocation and Assembly of Sugar Polymer Precursors.
abstract: Bacterial polysaccharides play an essential role in cell viability, virulence, and evasion of host defenses. Although the polysaccharides themselves are highly diverse, the pathways by which bacteria synthesize these essential polymers are conserved in both Gram-negative and Gram-positive organisms. By utilizing a lipid linker, a series of glycosyltransferases and integral membrane proteins act in concert to synthesize capsular polysaccharide, teichoic acid, and teichuronic acid. The pathways used to produce these molecules are the Wzx/Wzy-dependent, the ABC-transporter-dependent, and the synthase-dependent pathways. This chapter will cover the initiation, synthesis of the various polysaccharides on the cytoplasmic face of the membrane using nucleotide sugar precursors, and export of the nascent chain from the cytoplasm to the extracellular milieu. As microbial glycobiology is an emerging field in Gram-positive bacteria research, parallels will be drawn to the more widely studied polysaccharide biosynthesis systems in Gram-negative species in order to provide greater understanding of these biologically significant molecules.
authors: Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, N1G 2W1, Canada.
authors: Véronique L
authors: VL
authors: Taylor
authors: Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, N1G 2W1, Canada.
authors: Steven M
authors: SM
authors: Huszczynski
authors: Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, N1G 2W1, Canada. jlam@uoguelph.ca.
authors: Joseph S
authors: JS
authors: Lam
mesh_terms: D016667:Bacterial Capsules / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D002473:Cell Wall / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000502:physiology; D016695:Glycosyltransferases / Q000502:physiology; D006094:Gram-Positive Bacteria / Q000378:metabolism*; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis*; D013682:Teichoic Acids / Q000096:biosynthesis; D014574:Uronic Acids / Q000378:metabolism
chemical_list: D029968:Escherichia coli Proteins; D011135:Polysaccharides, Bacterial; D013682:Teichoic Acids; D014574:Uronic Acids; C010788:teichuronic acid; D016695:Glycosyltransferases; C513753:Wzy polymerase, E coli