Stereospecific Biosynthesis of β‐Methyltryptophan from <scp>L</scp>‐Tryptophan Features a Stereochemical Switch

Abstract

Make the switch: The three-enzyme cassette MarG/H/I is responsible for stereospecific biosynthesis of β-methyltryptophan from L-tryptophan (1). MarG/I convert 1 into (2S,3R)-β-methyltryptophan, while MarG/I combined with MarH convert 1 into (2S,3S)-β-methyltryptophan. MarH serves as a stereochemical switch by catalyzing the stereoinversion of the β-stereocenter.