Figure 4

MCS uncover robust L-threonine biosynthesis subnetwork. 10,655 minimal cut sets discovered using our approach target L-threonine synthesis via this 41 reaction subnetwork of E. coli metabolism. None of these reactions are 1- or 2-essential for L-threonine production, though 7 participate in size 1 or 2 MCS for peptidoglycan and L-methionine production. Though many of these cut sets are complex (i.e. involve 7 or more reactions) they can be intuitively understood as simultaneous attacks on a few distinct pathways that converge on L-threonine (thr-L) synthesis. For ease of presentation, we omit water and proton in the reaction depictions. Please refer to Table 2 for explanation of metabolite and reaction abbreviations. Please refer to the text for further discussion.