Glycolysis without pyruvate kinase in Clostridium thermocellum.
- Olson DG Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA; BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA. Electronic address: Daniel.G.Olson@Dartmouth.edu.
- Hörl M Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland.
- Fuhrer T Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland.
- Cui J Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA; BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA.
- Zhou J Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA; BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA.
- Maloney MI Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA; BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA.
- Amador-Noguez D Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA.
- Tian L Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA; BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA.
- Sauer U Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland.
- Lynd LR Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA; BioEnergy Science Center, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA. Electronic address: Lee.R.Lynd@Dartmouth.edu.
- 2016-12-05
Published in:
- Metabolic engineering. - 2017
(13)C flux analysis
Malate dehydrogenase
Malate shunt
Malic enzyme
Oxaloacetate decarboxylase
Pyruvate kinase
Biosynthetic Pathways
Carbon-13 Magnetic Resonance Spectroscopy
Clostridium thermocellum
Glucose
Glycolysis
Malates
Metabolic Flux Analysis
Metabolic Networks and Pathways
Models, Biological
Phosphoenolpyruvate
Pyruvate Kinase
Pyruvic Acid
English
The metabolism of Clostridium thermocellum is notable in that it assimilates sugar via the EMP pathway but does not possess a pyruvate kinase enzyme. In the wild type organism, there are three proposed pathways for conversion of phosphoenolpyruvate (PEP) to pyruvate, which differ in their cofactor usage. One path uses pyruvate phosphate dikinase (PPDK), another pathway uses the combined activities of PEP carboxykinase (PEPCK) and oxaloacetate decarboxylase (ODC). Yet another pathway, the malate shunt, uses the combined activities of PEPCK, malate dehydrogenase and malic enzyme. First we showed that there is no flux through the ODC pathway by enzyme assay. Flux through the remaining two pathways (PPDK and malate shunt) was determined by dynamic 13C labeling. In the wild-type strain, the malate shunt accounts for about 33±2% of the flux to pyruvate, with the remainder via the PPDK pathway. Deletion of the ppdk gene resulted in a redirection of all pyruvate flux through the malate shunt. This provides the first direct evidence of the in-vivo function of the malate shunt.
- Language
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- English
- Open access status
- bronze
- Identifiers
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- DOI 10.1016/j.ymben.2016.11.011
- PMID 27914869
- Persistent URL
- https://sonar.ch/global/documents/136888
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