aThe free energy was calculated assuming a transmembrane potential of -150 mV. bThis module exists in two variants (like the pathway it is derived from), depending on whether an AMP- or ADP-producing 3-hydroxypropyl-CoA/4-hydroxybutyryl-CoA synthase is used or not. In the here presented form, it corresponds to the crenarchaeal form. Both variants were considered, however, for the following analyses. cIn addition to the modules listed here, single reactions such as the pyruvate dehydrogenase complex or the pyruvate carboxylase were also used to connect metabolites. dThis cycle has the same working principle as the malyl-CoA-glycerate cycle (MCG cycle) presented in Yu et al. . Instead of turning 2 glyoxylate into glycerate which is then converted to oxaloacetate, this cycle directly uses the β-hydroxyaspartate cycle to turn 2 glyoxylate into oxaloacetate. A detailed pathway map can be found in Supplementary Figure S8B. eOriginal pathway in this context relates to the pathway in which the respective enzymes are usually found. Many of the connecting modules are subnetworks of the full, original pathways.