Figure 2
Constraints on network attributes. Constraints on network attributes from three perturbation responses. Response 1: deleting regulator r1 up-regulates enzyme e2. Constraint: edge sign s2 = -. Response 2: reducing metabolite m1 down-regulates enzyme e2. Constraint: s1·s2 = +. Response 3: reducing metabolite m1 decreases flux f2. Constraint: path 1 (magenta) and path 2 (cyan) are active, s1·s2 = +. Path 3 (brown) is inactive because its predicted response contradicts with the observed response.