A new activity for the [NiFe] uptake hydrogenase 1 of Escherichia coli (Hyd1) is presented. Direct reduction of biological flavin cofactors FMN and FAD is achieved using H2 as a simple, completely atom-economical reductant. The robust nature of Hyd1 is exploited for flavin reduction across a broad range of temperatures (25-70 °C) and extended reaction times. The utility of this system as a simple, easy to implement FMNH2 or FADH2 regenerating system is then demonstrated by supplying reduced flavin to Old Yellow Enzyme "ene-reductases" to support asymmetric alkene reductions with up to 100 % conversion. Hyd1 turnover frequencies up to 20.4 min-1 and total turnover numbers up to 20 200 were recorded during flavin recycling.
Robust [NiFe] hydrogenase 1 (Hyd1) from Escherichia coli is shown to have non‐native, H2‐dependent activity for FMN and FAD reduction. It is a promising recycling system for FMNH2 or FADH2 supply to flavoenzymes for chemical synthesis when coupled with an Old Yellow Enzyme ene‐reductase.
Keywords: asymmetric catalysis; biocatalysis; cofactor recycling; ene-reductase; hydrogenation.
© 2021 The Authors. Angewandte Chemie published by Wiley-VCH GmbH.