(A) The conserved reactions and (B) the conserved compounds among reconstructed metabolic models from the three phylogenetic domains. The models of the archaea M. barkeri, iAF692, the bacteria E. coli, iJR904, and the eukaryote S. cerevisiae, iND750, were compared to determine identical reactions and compounds contained in the models. All of the models were decompartmentalized so that only the reactions and cytosolic transporters were compared and not their location inside of the cell. The table gives information on the distribution of reactions in their respective pathways.