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Alterations of cellular physiology in Escherichia coli in response to oxidative phosphorylation impaired by defective F1-ATPase

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タイトル: Alterations of cellular physiology in Escherichia coli in response to oxidative phosphorylation impaired by defective F1-ATPase
著者: Noda, Sakiko 著作を一覧する
Takezawa, Yuji 著作を一覧する
Mizutani, Tomohiko 著作を一覧する
Asakura, Tomoaki 著作を一覧する
Nishiumi, Eiichiro 著作を一覧する
Onoe, Kazunori 著作を一覧する
Wada, Masaru 著作を一覧する
Tomita, Fusao 著作を一覧する
Matsushita, Kazunobu 著作を一覧する
Yokota, Atsushi 著作を一覧する
発行日: 2006年10月
出版者: American Society for Microbiology
誌名: Journal of Bacteriology
巻: 188
号: 19
開始ページ: 6869
終了ページ: 6876
出版社 DOI: 10.1128/JB.00452-06
抄録: The physiological changes in an F1-ATPase-defective mutant of Escherichia coli W1485 growing in a glucose-limited chemostat included a decreased growth yield (60%) and increased specific rates of both glucose consumption (168%) and respiration (171%). Flux analysis revealed that the mutant showed approximately twice as much flow in glycolysis but only an 18% increase in the tricarboxylic acid (TCA) cycle, owing to the excretion of acetate, where most of the increased glycolytic flux was directed. Genetic and biochemical analyses of the mutant revealed the downregulation of many TCA cycle enzymes, including citrate synthase, and the upregulation of the pyruvate dehydrogenase complex in both transcription and enzyme activities. These changes seemed to contribute to acetate excretion in the mutant. No transcriptional changes were observed in the glycolytic enzymes, despite the enhanced glycolysis. The most significant alterations were found in the respiratory-chain components. The total activity of NADH dehydrogenases (NDHs) and terminal oxidases increased about twofold in the mutant, which accounted for its higher respiration rate. These changes arose primarily from the increased (3.7-fold) enzyme activity of NDH-2 and an increased amount of cytochrome bd in the mutant. Transcriptional upregulation appeared to be involved in these phenomena. As NDH-2 cannot generate an electrochemical gradient of protons and as cytochrome bd is inferior to cytochrome bo3 in this ability, the mutant was able to recycle NADH at a higher rate than the parent and avoid generating an excess proton-motive force. We discuss the physiological benefits of the alterations in the mutant.
Rights: Copyright © 2006 American Society for Microbiology
資料タイプ: article (author version)
出現コレクション:雑誌発表論文等 (Peer-reviewed Journal Articles, etc)

提供者: 横田 篤


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