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Free-CoA mediated regulation of intermediary and central metabolism: An hypothesis, which accounts for the excretion of α-ketoglutarate during aerobic growth of E. coli on acetate

El-Mansi, Mansi (2005) Free-CoA mediated regulation of intermediary and central metabolism: An hypothesis, which accounts for the excretion of α-ketoglutarate during aerobic growth of E. coli on acetate. Research in Microbiology, 156 (8). pp. 874-879. ISSN 0923 2508

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Abstract/Description

During growth of Escherichia coli on acetate, phosphotransacetylase and -ketoglutarate dehydrogenase are in direct competition for their common co-factor, HS-CoA. Such competition is resolved in favour of phosphotransacetylase, thus rendering -ketoglutarate dehydrogenase rate-limiting (controlling) and, in turn, creating a bottleneck at the level of -ketoglutarate in the Krebs cycle. Accumulation of -ketoglutarate is then balanced by its excretion. Addition of pyruvate, glucose or any glycolytic intermediate to acetate-grown culture relieves such a bottleneck by reversing carbon flow through phosphotransacetylase to give acetyl phosphate and much-needed HS-CoA. The urgent need for HS-CoA by the primordial organism might therefore have provided the selective pressure that led to the co-evolution of phosphotransacetylase and the two-malate synthase isoenzymes.

Item Type: Article
Print ISSN: 0923 2508
Uncontrolled Keywords: Escherichia coli; Acetate metabolism; -Ketoglutarate excretion; Free CoA; Acetyl CoA; Phosphotransacetylase; Intermediary metabolism; Krebs cycle
University Divisions/Research Centres: Faculty of Health, Life & Social Sciences > School of Life Sciences
Dewey Decimal Subjects: 500 Science > 570 Life sciences; biology > 572 Biochemistry
500 Science > 570 Life sciences; biology > 579 Microorganisms, fungi & algae
Library of Congress Subjects: Q Science > QD Chemistry
Q Science > QR Microbiology
Item ID: 1722
Depositing User: RAE Import
Date Deposited: 14 Jul 2008 14:45
Last Modified: 05 Apr 2013 13:18
URI: http://researchrepository.napier.ac.uk/id/eprint/1722

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