CSDB: Search results

References to other databases: GTC:G06700QW, GlycomeDB:27636
Structural formula & atomic coordinates
Sweet-II 3D model
Show glycosyltransferases

Burkholderia cenocepacia is an opportunistic bacterium that infects patients with cystic fibrosis. B. cenocepacia strains J2315, K56-2, C5424, and BC7 belong to the ET12 epidemic clone, which is transmissible among patients. We have previously shown that transposon mutants with insertions within the O antigen cluster of strain K56-2 are attenuated for survival in a rat model of lung infection. From the genomic DNA sequence of the O antigen-deficient strain J2315, we have identified an O antigen lipopolysaccharide (LPS) biosynthesis gene cluster that has an IS402 interrupting a predicted glycosyltransferase gene. A comparison with the other clonal isolates revealed that only strain K56-2, which produced O antigen and displayed serum resistance, lacked the insertion element inserted within the putative glycosyltransferase gene. We cloned the uninterrupted gene and additional flanking sequences from K56-2 and conjugated this plasmid into strains J2315, C5424, and BC7. All the exconjugants recovered the ability to form LPS O antigen. We also determined that the structure of the strain K56-2 O antigen repeat, which was absent from the LPS of strain J2315, consisted of a trisaccharide unit made of rhamnose and two N-acetylgalactosamine residues. The complexity of the gene organization of the K56-2 O antigen cluster was also investigated by reverse transcription-PCR, revealing several transcriptional units, one of which also contains genes involved in lipid A-core oligosaccharide biosynthesis

Burkholderia, O-antigen, gene cluster, glycosyltransferase, clone, cystic fibrosis, lipopolysaccharide expression

NCBI PubMed ID: 15687196
Journal NLM ID: 2985120R
Publisher: American Society for Microbiology
Correspondence: mvalvano@uwo.ca
Institutions: Department of Microbiology and Immunology, University of Western Ontario, Dental Sciences Building Room 3014, London, Ontario, Canada N6A 5C1, Department of Microbiology, University of Virginia Health System, Charlottesville, Virginia2, Department of Biochemistry and Molecular Biology3 and Complex Carbohydrate Research Center,4 University of Georgia, Athens, Georgia
Methods: NMR, composition analysis, genetic methods

The lipopolysaccharide (LPS) is the major constituent of the outer leaflet of the outer membrane of Gram-negative bacteria. Its lipid A moiety is embedded in the membrane and serves as an anchor for the rest of the LPS molecule. The outermost repetitive glycan region of the LPS is linked to the lipid A through a core oligosaccharide (OS), and is designated as the O-specific polysaccharide (O-polysaccharide, OPS) or O-antigen. The O-antigen is the most variable portion of the LPS and provides serological specificity, which is used for bacterial serotyping. The OPS also provides protection to the microorganisms from host defenses such as complement mediated killing and phagocytosis, and is involved in interactions of bacteria with plants and bacteriophages. Studies of the OPSs ranging from the elucidation of their chemical structures and conformations to their biological and physico-chemical properties help improving classification schemes of Gram-negative bacteria. Furthermore, these studies contributed to a better understanding of the mechanisms of pathogenesis of infectious diseases, as well as provided information to develop novel vaccines and diagnostic reagents.

Lipopolysaccharide, synthesis, lipopolysaccharides, structure, Bacterial, host, O-antigen, O antigen, cell, O antigens, O-antigens, chemical, interaction, cells, PDF, chemical synthesis, biogenesis

Publication DOI: 10.1007/978-3-7091-0733-1_3
Publisher: Springer
Correspondence: knirel@ioc.ac.ru
Editors: Knirel YA, Valvano MA
Institutions: Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia

The trisaccharide repeating unit of an O-antigen derived from Burkholderia cenocepacia and its dimer, i.e., α-L-Rhap-(1→3)-α-D-GalpNAc-(1→3)-β-D-GalpNAc-O(CH2)3N3 (1) and α-L-Rhap-(1→3)-α-D-GalpNAc-(1→3)-β-D-GalpNAc-(1→4)-α-L-Rhap-(1→3)-α-D-GalpNAc-(1→3)-β-D-GalpNAc-O(CH2)3N3 (2), respectively, were synthesized via a highly convergent strategy. Glycosylation of galactosaminyl acceptor 4 with galactosaminyl trichloroacetimidate donor 5 was followed by condensation of resulting disaccharide acceptor 12 with rhamnosyl imidate donor 6 to furnish stereoselectively trisaccharyl thioglycoside 3, which was used as a key and common glycosyl donor for the construction of both 1 and 2. Title molecule 1 was prepared by glycosylation of 3-azidopropanol with 3 and subsequently global deprotection, whereas coupling reaction of 3 with a trisaccharide acceptor 21 containing an 2,3-O-position acetonide-modified rhamnose residue, followed by global deprotection, generated the dimer 2 in a convergent [3 + 3] manner.

Lipopolysaccharide, synthesis, O-antigen, repeating unit, Burkholderia cenocepacia

NCBI PubMed ID: 28917967
Publication DOI: 10.1016/j.carres.2017.09.001
Journal NLM ID: 0043535
Publisher: Elsevier
Correspondence: guofenggu@sdu.edu.cn; zguo@chem.ufl.edu
Institutions: College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Normal University, 88 Wenhua Dong Lu, Jinan 250014, PR China, Department of Chemistry, University of Florida, 214 Leigh Hall, Gainesville, FL 32611, United States, National Glycoengineering Research Center, Shandong Provincial Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, 27 Shanda Nan Lu, Jinan 250010, PR China
Methods: 13C NMR, 1H NMR, TLC, chemical synthesis, optical rotation measurement, HR-ESI-MS