Erroneous energy-generating cycles in published genome scale metabolic networks: Identification and removal
Fig 6
Examples of EGCs found in published genome-scale models.
Green/red: metabolites; blue: reactions, linking substrates and products; orange: direction of the energy gradient utilized by the energy dissipation reaction. (A) The simplest identified cycle, which links a Na+/proton antiporter (exporting Na+ in exchange for a single proton) and a Malate/proton symporter (importing Malate together with two protons) via a Malate/Na+ symporter. (B) A cycle involving two antiporters and one symporter, driven by a transporter that translocates tartrate from the periplasm to the cytosol. (C) A NADH:menaquinone oxidoreductase, which translocates protons in the process of transferring electrons from NADH to Menaquinone 8, driven by a chain of four enzymes. (D) rxn00379 creates Adenosine 5'-phosphosulfate from ATP and sulfate. The equivalent sulfate adenyltransferase rxn09240 catalyzes the backward reaction, but charges a GTP in addition to the ATP.