Figure 6

Feedback inhibition at different positions of the pathway.(A) Schematic representation of the different considered pathway configurations. (B) Median regulatory effort in each enzyme for different topologies of feedback inhibition. Runs without inhibition are depicted in white. Boxplots for the complete range of values are presented in Additional file 1: Figures S21-S24. (C) Overall regulatory effort measured as the sum of the median values for all the considered cases. (D) Example pathways from aromatic amino acid (upper pathway) as well as lysine, methionine and threonine biosynthesis (lower pathway) in which the identified regulatory strategies are utilized in E. coli. Gene names have been omitted for clarity. Dotted arrows correspond to lumped sequences of reactions, grey dashed arrows correspond to feedback inhibition. Figure adapted from the corresponding super-pathways in EcoCyc [19]. Abbreviations: E4P, D-erythrose 4-phosphate; Chor, chorismate; Trp, L-tryptophan; Pphn, prephenate; Phe, L-Phenylalanine; Tyr, L-tyrosine; Asp, L-aspartate; Aspsa, L-aspartate 4-semialdehyde; Lys, L-lysine; Hom, L-homoserine; Met, L-methionine; Thr, L-threonine.