Conserved glucose responding modules between B. subtilis and E. coli. Whereas there is extensive rewiring in the regulatory network, some modules have conserved their physiological functions and expression profile, showing the high plasticity of regulatory networks in terms of evolution. Dashed thin lines show orthology relations, whereas blue dash-dot lines bound modules. Green ellipses indicate repressed genes; red ones show activated genes and grey ones indicate genes, which are not significantly expressed. E. coli modules IDs are taken from Gutierrez-Rios et al. . Regarding the aspartate catabolism module, it has been suggested that L-aspartase encoded by ansB is an strictly catabolic enzime (catalyzing the reaction aspartate → fumarate + NH4+), thus providing carbon skeletons to Krebs cycle.