Energy dependence of O-antigen synthesis in Salmonella typhimurium
Autor: | Pamela A. Marino, M. J. Osborn, Barbara C. McGRATH |
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Rok vydání: | 1991 |
Předmět: |
Lipopolysaccharides
Salmonella typhimurium Biological Transport Active Oligosaccharides Microbiology Membrane Potentials chemistry.chemical_compound Biosynthesis Transferase Nucleotide Phosphorylation Molecular Biology chemistry.chemical_classification Antigens Bacterial biology ATP synthase Terpenes Chemiosmosis Galactose O Antigens Active site Hydrogen-Ion Concentration carbohydrates (lipids) Enzyme chemistry Biochemistry biology.protein Dinitrophenol Energy Metabolism Uridine Monophosphate Mannose Dinitrophenols Research Article |
Zdroj: | Journal of Bacteriology. 173:3128-3133 |
ISSN: | 1098-5530 0021-9193 |
Popis: | The uncoupler 2,4-dinitrophenol prevents in vivo synthesis of O antigen in Salmonella typhimurium by inhibiting the first reaction of the pathway, formation of galactosyl-pyrophosphoryl-undecaprenol. Inhibition was observed only in intact cells; dinitrophenol had no effect on activity of the synthase enzyme in isolated membrane fractions. In vivo inhibition could not be explained by changes in intracellular nucleotide pools or a shift in the equilibrium of the reaction and appeared to be specific for the first step in the pathway. Neither the subsequent mannosyl transferase, which catalyzes formation of the trisaccharide-lipid intermediate, mannosyl-rhamnosyl-galactosyl-pyrophosphoryl-undecaprenol, nor O-antigen polymerase was inhibited. In addition, incorporation of galactose into core lipopolysaccharide was only modestly inhibited under conditions in which O-antigen synthesis was abolished. The results suggest that maintenance of proton motive force is required for access of substrate, UDP-galactose and/or undecaprenyl phosphate, to the active site of the galactosyl-pyrophosphoryl-undecaprenol synthase enzyme. |
Databáze: | OpenAIRE |
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