Aliphatic iron(II)- and 2-(oxo)-glutarate-(Fe/2OG)-dependent oxidative halogenases alter the relative orientation of the substrate C-H and ferryl Fe-O bonds to control the partition between hydroxylation and chlorination/bromination outcomes. In several different Fe/2OG halogenase platforms, crystallographic and spectroscopic characterization of reactant and intermediate states suggests that the enzymes accomplish such control via direction of the oxo group into one of two cis-related coordination sites, termed inline and offline. The offline oxo configuration is proposed to favor halogenation and other non-canonical outcomes. We have developed new tools and methods to characterize distinct ferryl geometries in Fe/2OG enzymes that will enable direct test of this hypothesis, particularly in halogenase enzymes that act on freestanding small molecule substrates. We have also demonstrated successful reprogramming of an Fe/2OG hydroxylase into an aliphatic halogenase. Optimization and characterization of this engineered catalyst offers an alternative approach to understanding the factors that control the relative disposition of substrate and intermediate in this important subclass of Fe/2OG enzymes. This presentation will accompany a talk on computational insights into substrate positioning and protein-protein dynamics in more complex carrier-protein dependent Fe/2OG halogenases.

New experimental approaches to understand control of reaction outcome in iron(II)- and 2-(oxo)-glutarate-dependent halogenases

2019 Fall National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.