Requirement for the proton-pumping NADH dehydrogenase I of Escherichia coli in respiration of NADH to fumarate and its bioenergetic implications.
In Escherichia coli the expression of the nuo genes encoding the proton pumping NADH dehydrogenase I is stimulated by the presence of fumarate during anaerobic respiration. The regulatory sites required for the induction by fumarate, nitrate and O2 are located at positions around -309, -277, and downstream of -231 bp, respectively, relative to the transcriptional-start site. The fumarate regulator has to be different from the O2 and nitrate regulators ArcA and NarL. For growth by fumarate respiration, the presence of NADH dehydrogenase I was essential, in contrast to aerobic or nitrate respiration which used preferentially NADH dehydrogenase II. The electron transport from NADH to fumarate strongly decreased in a mutant lacking NADH dehydrogenase I. The mutant used acetyl-CoA instead of fumarate to an increased extent as an electron acceptor for NADH, and excreted ethanol. Therefore, NADH dehydrogenase I is essential for NADH-->fumarate respiration, and is able to use menaquinone as an electron acceptor. NADH-->dimethylsulfoxide respiration is also dependent on NADH dehydrogenase I. The consequences for energy conservation by anaerobic respiration with NADH as a donor are discussed.
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Institut für Mikrobiologie und Weinforschung, Universität Mainz, Germany.
Bongaerts
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J
Vlad
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Unden
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D000085:Acetates / Q000378:metabolism; D000693:Anaerobiosis; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D004579:Electron Transport; D042967:Electron Transport Complex I; D004734:Energy Metabolism / Q000187:drug effects; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D000431:Ethanol / Q000378:metabolism; D005650:Fumarates / Q000378:metabolism* / Q000494:pharmacology; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D009243:NAD / Q000378:metabolism*; D009247:NADH, NADPH Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D017494:Proton Pumps / Q000378:metabolism*
D000085:Acetates; D005650:Fumarates; D017494:Proton Pumps; D009243:NAD; D000431:Ethanol; D009247:NADH, NADPH Oxidoreductases; D042967:Electron Transport Complex I; D004121:Dimethyl Sulfoxide