Mutations that improve efficiency of a weak-link enzyme are rare compared to adaptive mutations elsewhere in the genome.
Morgenthaler AB, Kinney WR, Ebmeier CC, Walsh CM, Snyder DJ, Cooper VS, Old WM, Copley SD. Mutations that improve efficiency of a weak-link enzyme are rare compared to adaptive mutations elsewhere in the genome. Elife. 2019 12 09; 8.