Equipping Saccharomyces cerevisiae with an Additional Redox Cofactor Allows F₄₂₀-Dependent Bioconversions in Yeast

Industrial application of the natural deazaflavin cofactor F₄₂₀ has high potential for the enzymatic synthesis of high value compounds. It can offer an additional range of chemistry to the use of well-explored redox cofactors such as FAD and their respective enzymes. Its limited access through organisms that are rather difficult to grow has urged research on the heterologous production of F₄₂₀ using more industrially relevant microorganisms such as Escherichia coli. In this study, we demonstrate the possibility of producing this cofactor in a robust and widely used industrial organism, Saccharomyces cerevisiae, by the heterologous expression of the F₄₂₀ pathway. Through careful selection of involved enzymes and some optimization, we achieved an F₄₂₀ yield of ∼1.3 μmol/L, which is comparable to the yield of natural F₄₂₀ producers. Furthermore, we showed the potential use of F₄₂₀-producing S. cerevisiae for F₄₂₀-dependent bioconversions by carrying out the whole-cell conversion of tetracycline. As the first demonstration of F₄₂₀ synthesis and use for bioconversion in a eukaryotic organism, this study contributes to the development of versatile bioconversion platforms.