Combining a Nitrogenase Scaffold and a Synthetic Compound into an Artificial Enzyme

Nitrogenase catalyzes substrate reduction at its cofactor center ([(Cit)MoFe 7 S 9 C] n − ; designated M‐cluster). Here, we report the formation of an artificial, nitrogenase‐mimicking enzyme upon insertion of a synthetic model complex ([Fe 6 S 9 (SEt) 2 ] 4− ; designated Fe 6 RHH ) into the catalytic component of nitrogenase (designated NifDK apo ). Two Fe 6 RHH clusters were inserted into NifDK apo , rendering the conformation of the resultant protein (designated NifDK Fe ) similar to the one upon insertion of native M‐clusters. NifDK Fe can work together with the reductase component of nitrogenase to reduce C 2 H 2 in an ATP‐dependent reaction. It can also act as an enzyme on its own in the presence of Eu II DTPA, displaying a strong activity in C 2 H 2 reduction while demonstrating an ability to reduce CN − to C 1 –C 3 hydrocarbons in an ATP‐independent manner. The successful outcome of this work provides the proof of concept and underlying principles for continued search of novel enzymatic activities based on this approach.