Electron Transfer Reactions in Biological Nitrogen Fixation

Abstract

Abstract In this review, we summarize our recent efforts toward understanding electron transfer (ET) processes in nitrogenase, the only enzyme capable of reducing dinitrogen to ammonia. We discuss new structural and biochemical perspectives on the role of ATP‐dependent interactions between the two components of nitrogenase, Fe‐protein (FeP) and MoFe‐protein (MoFeP), and how these interactions may regulate interprotein ET and catalysis. We also discuss the implications of our work on FeP‐ and ATP‐independent, photoredox‐activated substrate reduction by MoFeP. Elucidating why and how ATP‐hydrolysis is needed to control electron and proton flow in nitrogenase is not only a fundamentally important question in biological redox chemistry and energy transduction, but it also holds the key to understanding the intimate mechanism of dinitrogen reduction.