Figure 2. Effect of the double knockout of glyceraldehyde-3-phosphate dehydrogenase (GAPD) and cytochrome c oxidase (CYOR) on the optimal flux distribution for virus production under minimal media conditions with uptake fluxes set to -10 mmol∙gDW-1∙h-1. (A)Distribution of the producing (‘in’) and consuming (‘out’) fluxes for valine in the cytosol and glutamate in the mitochondrial matrix. For each metabolite, the in and out fluxes have been computed for the unmodified model (left) and for the double knockout of GAPD and CYOR (right). (B) Cartoon representation of the reaction network involving valine and other metabolites, with reaction fluxes from normal and perturbation conditions colour-mapped onto reaction arrows. The upper panel represents the flux distribution in the normal condition, while the lower panel represents flux distribution under perturbation, i.e. when both GAPD and CYOR are knocked out. The light grey rectangle represents the mitochondrial compartment. Metabolite notations used are: 3-methyl-2-oxobutanoate (3mob), 4-methyl-2-oxopentanoate (4mop), alpha-keto-glutarate (akg), 4-oxobutanoate (sucsal), gamma-aminobutyric acid (4abut).