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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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Title: Alterations of cellular physiology in Escherichia coli in response to oxidative phosphorylation impaired by defective F1-ATPase
Authors: Noda, Sakiko Browse this author
Takezawa, Yuji Browse this author
Mizutani, Tomohiko Browse this author
Asakura, Tomoaki Browse this author
Nishiumi, Eiichiro Browse this author
Onoe, Kazunori Browse this author
Wada, Masaru Browse this author
Tomita, Fusao Browse this author
Matsushita, Kazunobu Browse this author
Yokota, Atsushi Browse this author →KAKEN DB
Issue Date: Oct-2006
Publisher: American Society for Microbiology
Journal Title: Journal of Bacteriology
Volume: 188
Issue: 19
Start Page: 6869
End Page: 6876
Publisher DOI: 10.1128/JB.00452-06
PMID: 16980490
Abstract: 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
Type: article (author version)
URI: http://hdl.handle.net/2115/17010
Appears in Collections:農学院・農学研究院 (Graduate School of Agriculture / Faculty of Agriculture) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)

Submitter: 横田 篤

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