How directed evolution reshapes the energy landscape in an enzyme to boost catalysis
Category
Published on
Type
journal-article
Author
Renee Otten and Ricardo A. P. Pádua and H. Adrian Bunzel and Vy Nguyen and Warintra Pitsawong and MacKenzie Patterson and Shuo Sui and Sarah L. Perry and Aina E. Cohen and Donald Hilvert and Dorothee Kern
Citation
Otten, R. et al., 2020. How directed evolution reshapes the energy landscape in an enzyme to boost catalysis. Science, p.eabd3623. Available at: http://dx.doi.org/10.1126/science.abd3623.
Abstract
The advent of biocatalysts designed computationally and optimized by laboratory evolution provides an opportunity to explore molecular strategies for augmenting catalytic function. Applying a suite of NMR, crystallographic, and stopped-flow techniques to an enzyme designed for an elementary proton transfer reaction, we show how directed evolution gradually altered the conformational ensemble of the protein scaffold to populate a narrow, highly active conformational ensemble and achieve a nearly billionfold rate acceleration. Mutations acquired during optimization enabled global conformational changes, including high-energy backbone rearrangements, that cooperatively organized the catalytic base and oxyanion stabilizer, thus perfecting transition-state stabilization. Explicit sampling of conformational sub-states during design, and specifically stabilizing productive over all unproductive conformations, could speed up the development of protein catalysts for many chemical transformations.
