Capsular polysaccharides biosynthesis

Beck von Bodman, S., Farrand, S, K. Capsular polysaccharide biosynthesis and pathogenicity in Erwinia stewartii require induction by an N-acylhomoserine lactone autoinducer. J Bacteriol 1995 177 5000-5008. 

Llull D, Lopez R, Garcia E (2001) Genetic bases and medical relevance of capsular polysaccharide biosynthesis in pathogenic streptococci. Curr Mol Med 1 475-491... 

The type-specific capsular polysaccharide from Streptococcus pneumoniae type 5 contains 2-acetamido-2,6-dideoxy- -D-x>>/o-hexopyranosyl-4-ulose residues (17). Sugar nucleotides of hexos-4-uloses are important intermediates in the transformation of sugars during the biosynthesis, but this is the only known example of such a sugar as a polysaccharide component. 

In the biosynthesis of the capsular polysaccharide from Xanthomonas campestris, the modification was shown265 to occur at the level of a polyprenyl pentasaccharide diphosphate intermediate prior to polymerization of the repeating units, and enolpyruvate phosphate was a precursor of the pyruvic acid residues. A similar observation was made during a study of the biosynthesis of Rhizobium meliloti exopolysaccharide.266... 

Some results of studies on the biosynthesis of two other Klebsiella capsular polysaccharides have also been reported. In the case of type 2 specific polysaccharide336 (27), incorporation of the D-mannosyl group from GDP-Man into glycosyl-lipids and the polymer, catalyzed by a cell-envelope... 

Some data concerning the biosynthesis of S. pneumoniae types 1 and 8 capsular polysaccharides were mentioned in the review,374 but experimental details were not reported. 

The block mechanism of chain assembly is characteristic for polymeric chains of the UGT type (see Salmonella O-specific polysaccharides 10-12 and 18) and the UG type (see capsular polysaccharides 25, 27, and 33), with UDP-activated sugars serving as initiators of chain growth. It seems rather safe to suggest that the biosynthesis of other polymers of these types occurs through a block mechanism as well. 

The 3-deoxy-D-ma/ino-2-octulosonic acid 8-phosphate synthase (KDO synthase or KdoS EC 4.1.2.16) is an enzyme involved in the biosynthesis of the eight-carbon sugar KDO [63], a constituent of the capsular polysaccharides (K-antigens) and outer membrane lipopolysaccharides (LPS, endotoxin) of Gram-negative bacteria [156], as well as of the cell wall of algae and a variety of plants [157], In vivo, the enzyme catalyzes the irreversible addition of 26 to D-arabinose 5-phosphate (Ara5P, 32) to form KDO 8-phosphate 33 [158]. The... 

Whitfield, C. Biosynthesis and assembly of capsular polysaccharides in Escherichia coli. Annu Rev Biochem 75 (2006) 39-68. 

Hodson N, Griffiths G, Cook N, Pourhossein M, Gottfridson E, Lind T, Lidholt K, Roberts IS. Identification that KfiA, a protein essential for the biosynthesis of the Escherichia coh K5 capsular polysaccharide, is an alpha-UDP-GlcNAc glycosyltransferase. The formation of a membrane-associated K5 biosynthetic complex requires KfiA, KfiB, and KfiC. J. Biol. Chem. 2000 275 27311-27315. 

Vaccination with Prevenar reduced seven serotypes of Sp included in the conjugate vaccines. An increase in circulation of serotype 19A, not included in a vaccine, warns of the possibility of a replacement phenomenon [144]. Capsular polysaccharide serogroup seems not to be a fixed attribute of a strain for Nm [145] and Sp [146], as the exchange of single gene cassettes involved in CPS biosynthesis is a frequent process that could affect the speed of a replacement phenomenon. 

In 1953, Bemheimer demonstrated that washed, resting cells from Type III Pneumococcus could synthesize Sill in the presence of D-glucose or certain other monosaccharides, Mg , K , P04 , and oxygen. Biosynthesis of the capsular polysaccharides was shown later to depend on the presence of uridine nucleotides. Similar precursors have been implicated in the biosynthesis of cellulose, chitin, /3-d-(1—>3)-glucan, glycogen, and hyaluronic acid. ... 

This chapter will review the current mechanisms strictly operating in the biogenesis of the 0-specific EPS. More comprehensive information on the biosynthesis and assembly of other EPS components and capsular polysaccharides can be found in recent reviews. ... 

The functions of lipid intermediates in the biosynthesis of a man-nan, a bacterial capsular polysaccharide, a cell-wall lipopolysac-charide, and a cell-wall peptidoglycan are respectively discussed in Sections dealing with each (see Sections V,6, p. 396 VI,5,6, and 7, pp. 408, 418, 428). In all these syntheses, the glycosyl groups are... 

Two sulfone-based nucleoside diphosphate isosters (71a,b) has been synthesised and reported by Gervay-Hague to be inhibitors of Neisseria meningitidis CMP-sialic acid synthetase, which is a key enzyme in the biosynthesis of capsular polysaccharides required for bacterial infection. The synthetic methodology includes a condensation reaction of the nucleoside aldehydes with bisphosphonate Horner-Wadsworth-Emmons reagents (Scheme 4). The deprotection sequence was crucial for the appropriate completion of the synthetic targets. 

A book dealing with the surface carbohydrates of prokaryotic cells has discussed, among other topics, capsular polysaccharide antigens, immunological expression, the structures of bacterial polysaccharides,and the biosynthesis of capsular polysaccharides. ... 

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