Structure of the K128 capsular polysaccharide produced by Acinetobacter baumannii KZ-1093 from Kazakhstan. (1st November 2019)

• Record Type: Journal Article
• Authors: Arbatsky, Nikolay P.; Kasimova, Anastasiya A.; Shashkov, Alexander S.; Shneider, Mikhail M.; Popova, Anastasiya V.; Shagin, Dmitry A.; Shelenkov, Andrey A.; Mikhailova, Yuliya V.; Yanushevich, Yurii G.; Azizov, Ilya S.; Edelstein, Mikhail V.; Hall, Ruth M.; Kenyon, Johanna J.; Knirel, Yuriy A.
• Is Part Of: Carbohydrate research. Volume 485(2019)
• Publication Date: 2019-11-01
• Subjects: Acinetobacter baumannii -- Capsular polysaccharide -- K locus -- Glycosyltransferase -- Wzy polymerase; Carbohydrates -- Periodicals; Chemistry, Organic -- Periodicals; Biochemistry -- Periodicals; Carbohydrates -- Periodicals; Chimie organique -- Périodiques; Glucides -- Périodiques; Biochemistry; Carbohydrates; Chemistry, Organic; Periodicals; Electronic journals; 507.78
• DOI: 10.1016/j.carres.2019.107814
• Languages: English
• ISSNs: 0008-6215

Abstract

Abstract: The structure of the K128 capsular polysaccharide (CPS) produced by Acinetobacter baumannii isolate KZ-1093 from Kazakhstan was established by sugar analysis and Smith degradation along with 1D and 2D 1 H and 13 C NMR spectroscopy. The CPS was found to consist of branched pentasaccharide repeating units containing only neutral sugars, and its composition and topology are closely related to those of the A. baumannii K116 CPS. The K128 and K116 oligosaccharide units differ in the linkage between the disaccharide side chain and the main chain, with a β-(1 → 6) linkage in K128 replacing a β-(1 → 4) linkage in K116. The linkages between the repeating units in the K128 and K116 CPSs are also different, with K128 units linked by β-d -Gal p NAc-(1 → 4)-d -Gal p, and β-d -Gal p NAc-(1 → 3)-d -Gal p linkages between K116 units. The KZ-1093 genome was sequenced and the CPS biosynthesis gene cluster at the chromosomal K locus was designated KL128. Consistent with the CPS structures, KL128 differs from KL116 in one glycosyltransferase gene and the gene for the Wzy polymerase. In KL128, the gtr200 glycosyltransferase gene replaces gtr76 in KL116, and Gtr200 was therefore assigned to the different β-d -Gal p NAc-(1 → 6)-d -Gal p linkage in K128. Similarly, the WzyK128 polymerase could be assigned to the β-d -Gal p NAc-(1 → 4)-d -Gal p linkage between the K128 units. Graphical abstract: Image 1 Highlights: The Acinetobacter baumannii K128 capsule structure is closely related to the K116 capsule structure. The function of the glycosyltransferases, Wzy polymerases and initiating transferase were unambiguously assigned. The KL128 gene cluster includes genes for glycosyltransferases and simple sugar synthesis.