title: The KL24 gene cluster and a genomic island encoding a Wzy polymerase contribute genes needed for synthesis of the K24 capsular polysaccharide by the multiply antibiotic resistant Acinetobacter baumannii isolate RCH51.
abstract: The whole-genome sequence of the multiply antibiotic resistant Acinetobacter baumannii isolate RCH51 belonging to sequence type ST103 (Institut Pasteur scheme) revealed that the set of genes at the capsule locus, KL24, includes four genes predicted to direct the synthesis of 3-acetamido-3,6-dideoxy-d-galactose (d-Fuc3NAc), and this sugar was found in the capsular polysaccharide (CPS). One of these genes, fdtE, encodes a novel bifunctional protein with an N-terminal FdtA 3,4-ketoisomerase domain and a C-terminal acetyltransferase domain. KL24 lacks a gene encoding a Wzy polymerase to link the oligosaccharide K units to form the CPS found associated with isolate RCH51, and a wzy gene was found in a small genomic island (GI) near the cpn60 gene. This GI is in precisely the same location as another GI carrying wzy and atr genes recently found in several A. baumannii isolates, but it does not otherwise resemble it. The CPS isolated from RCH51, studied by sugar analysis and 1D and 2D 1H and 13C NMR spectroscopy, revealed that the K unit has a branched pentasaccharide structure made up of Gal, GalNAc and GlcNAc residues with d-Fuc3NAc as a side branch, and the K units are linked via a β-d-GlcpNAc-(1→3)-β-d-Galp linkage formed by the Wzy encoded by the GI. The functions of the glycosyltransferases encoded by KL24 were assigned to formation of specific bonds. A correspondence between the order of the genes in KL24 and other KL and the order of the linkages they form was noted, and this may be useful in future predictions of glycosyltransferase specificities.
authors.affiliation: School of Molecular Bioscience, The University of Sydney, Sydney, Australia.|Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Australia.
authors.forename: Johanna J
authors.initials: JJ
authors.lastname: Kenyon
authors.affiliation: N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia.|Higher Chemical College of the Russian Academy of Sciences, D. I. Mendeleev University of Chemical Technology of Russia, Moscow, Russia.
authors.forename: Anastasiya A
authors.initials: AA
authors.lastname: Kasimova
authors.affiliation: M. M. Shemyakin and Y. A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Mikhail M
authors.initials: MM
authors.lastname: Shneider
authors.affiliation: N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Shashkov
authors.affiliation: N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Nikolay P
authors.initials: NP
authors.lastname: Arbatsky
authors.affiliation: Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia.|State Research Center for Applied Microbiology and Biotechnology, Obolensk, Moscow Region, Russia.
authors.forename: Anastasiya V
authors.initials: AV
authors.lastname: Popova
authors.affiliation: M. M. Shemyakin and Y. A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Konstantin A
authors.initials: KA
authors.lastname: Miroshnikov
authors.affiliation: School of Molecular Bioscience, The University of Sydney, Sydney, Australia.|School of Life and Environmental Sciences, The University of Sydney, Sydney, Australia.
authors.forename: Ruth M
authors.initials: RM
authors.lastname: Hall
authors.affiliation: N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Yuriy A
authors.initials: YA
authors.lastname: Knirel
mesh_terms: D000116:Acetylgalactosamine / Q000031:analogs & derivatives / Q000096:biosynthesis; D040981:Acinetobacter baumannii / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D016667:Bacterial Capsules / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D005643:Fucose / Q000031:analogs & derivatives / Q000096:biosynthesis; D016680:Genome, Bacterial / Q000235:genetics; D044404:Genomic Islands / Q000235:genetics; D016695:Glycosyltransferases / Q000235:genetics*; D006801:Humans; D008565:Membrane Proteins / Q000096:biosynthesis / Q000235:genetics*; D005810:Multigene Family / Q000235:genetics; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis*
chemical_list: C478186:3-acetamido-3,6-dideoxy-D-galactose; D001426:Bacterial Proteins; D008565:Membrane Proteins; D011135:Polysaccharides, Bacterial; D005643:Fucose; D016695:Glycosyltransferases; D000116:Acetylgalactosamine