K87 capsular polysaccharide (CPS) was isolated from Acinetobacter baumannii isolate LUH5547 that carries the KL87 capsule biosynthesis gene cluster at the chromosomal K locus. Studies by sugar analysis, selective chemical cleavages, and 1D and 2D 1H and 13C NMR spectroscopy showed that the CPS has a branched heptasaccharide repeat (K unit) containing one residue each of d-glucose (d-Glсp), d-glucuronic acid (d-GlсpA), N-acetyl-d-glucosamine (d-GlсpNAc), 6-deoxy-l-talose (l-6dTalp), and three residues of l-rhamnose (l-Rhap). The following structure of the CPS was established: →3)-α-L-Rhap-(1→2)-α-L-Rhap-(1→3)-α-L-6dTalp-(1→3)-β-D-GlcpNAc-(1→2↑1β-D-GlcpA-(4←1)-α-D-Glcp(2←1)-α-L-Rhap The position of a minor O-acetyl group present in the CPS was not determined. Functions of enzymes coded by genes in the KL87 gene cluster were tentatively assigned and found to be consistent with the CPS structure.
biosynthesis, structure, capsular, polysaccharide, group, Acinetobacter, Acinetobacter baumannii, capsular polysaccharide, 6-deoxy-L-talose, K locus, K87
NCBI PubMed ID: 34555685Publication DOI: 10.1016/j.carres.2021.108439Journal NLM ID: 0043535Publisher: Elsevier
Correspondence: johanna.kenyon@qut.edu.au
Institutions: N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia, M. M. Shemyakin & Y. A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia, State Research Center for Applied Microbiology and Biotechnology, Obolensk, Moscow Region, Russia, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia, School of Life and Environmental Sciences, The University of Sydney, Sydney, Australia, Centre for Immunology and Infection Control, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology. Brisbane, Australia
Methods: 13C NMR, 1H NMR, NMR-2D, partial acid hydrolysis, sugar analysis, GLC, Smith degradation, de-O-acetylation, HPLC, GPC, bioinformatic analysis
Found