Evolutionary Cycles for Pericyclic Reactions – Or Why We Keep Mutating Mutases

Abstract

Directed evolution strategies are being applied ever more frequently to develop novel and improved enzymes for many applications, including those contributing to 'white biotechnology'. In addition to engineering new biocatalysts, evolutionary strategies are equally suited to the elucidation of enzyme structure and function. Here, we illustrate with selected examples from our own work on chorismate mutases how such strategies can be employed to address a range of fundamental questions. Over the last decade, this model system, which was once considered to be a 'very simple' enzyme from the shikimate pathway, has afforded many – sometimes surprising – discoveries about biocatalysis. It has also taught us how to upgrade evolutionary approaches to overcome technical hurdles. Both the new insights and the methodological improvements should enhance our ability to tailor enzymes for novel uses.

Keywords

• Chorismate mutase
• Directed evolution
• Enzyme structure and function
• Isochorismate pyruvate lyase
• Selection in vivo