Identifying a key spot for electron mediator-interaction to tailor CO dehydrogenase’s affinity

Abstract

Carbon monoxide dehydrogenases (CODH) employ artificial electron mediators like viologens for biocatalysis, but little is known about the interaction between the mediators and the enzyme. Here, the authors discover the critical site for viologen interactions at the D-cluster of Carboxydothermus hydrogenoformans CODH2 via alanine mutations and crystallography, and report variants with increased ethyl viologen affinity.