title: Aerobic and anaerobic regulation of the ubiCA operon, encoding enzymes for the first two committed steps of ubiquinone biosynthesis in Escherichia coli.
abstract: The ubiCA operon of Escherichia coli encodes enzymes for the first two steps of ubiquinone biosynthesis. A monolysogen (ubiC-lacZ operon fusion) was constructed to study ubiCA regulation. Expression was higher during aerobic growth than anaerobically, and increased with rate of oxygen supply. Although ubiquinone is implicated in antioxidant roles, ubiC expression was not elevated in response to hydrogen peroxide or the redox cycling agent, paraquat. Glucose repressed expression and mutation of cya (encoding adenylate cyclase) increased expression. Anaerobically utilised electron acceptors (nitrite, nitrate, fumarate) did not affect expression. ubiC expression appears to be negatively regulated by Fnr and IHF.
authors.affiliation: Krebs Institute for Biomolecular Research, Department of Molecular Biology and Biotechnology, The University of Sheffield, Western Bank, UK.
authors.forename: B
authors.initials: B
authors.lastname: Søballe
authors.forename: R K
authors.initials: RK
authors.lastname: Poole
mesh_terms: D000332:Aerobiosis; D019883:Alkyl and Aryl Transferases; D000693:Anaerobiosis; D001483:Base Sequence; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D005838:Genotype; D005947:Glucose / Q000494:pharmacology; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007700:Kinetics; D008969:Molecular Sequence Data; D009876:Operon; D007652:Oxo-Acid-Lyases / Q000096:biosynthesis* / Q000235:genetics; D010269:Paraquat / Q000494:pharmacology; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D014166:Transferases / Q000096:biosynthesis* / Q000235:genetics; D014451:Ubiquinone / Q000096:biosynthesis*; D001616:beta-Galactosidase / Q000096:biosynthesis
chemical_list: D011993:Recombinant Fusion Proteins; D014451:Ubiquinone; D006861:Hydrogen Peroxide; D014166:Transferases; D019883:Alkyl and Aryl Transferases; C021386:4-hydroxybenzoate polyprenyltransferase; D001616:beta-Galactosidase; D007652:Oxo-Acid-Lyases; C075960:chorismate pyruvate lyase; D005947:Glucose; D010269:Paraquat