Figure 5.
Design trade-offs and constraints for the RBS strengths. (a) Design trade-off: a low bi/b1 ratio yields low steady-state enzyme levels and high steady-state intermediate levels, whereas high ratios increase enzyme concentrations in favour of lower concentrations for the intermediates. (b) Design constraint: the feasible RBS region prevents the accumulation of intermediates and product; the region is defined by conditions (3.9) and (3.10). (c) Tighter promoters enlarge the feasible region, whereas (d) leakier promoters or higher substrate concentrations tighten the constraints. (Online version in colour.)