Mechanism of Nitrogen Fixation by Nitrogenase: The Next Stage

Nitrogen fixation has a profound agronomic, economic, and ecological impact owing to the fact that the availability of fixed nitrogen represents the factor that most frequently limits agricultural production throughout the world. The trapping and characterization of five nitrogenase catalytic intermediates, which correspond to three of the five stages involved in binding and reduction of nitrogen most especially the Janus intermediate, E4, and including the nitrogenous intermediate states have identified the 'prompt-alternating (P-A)'. Until now, the data indicating that some H2 must be evolved during N2 reduction has been viewed as being much more compelling than the data indicating an obligatory evolution of one H2 for every N 2 reduced. The test reaction highlighted the role of N2 as cocatalyst in reductions catalyzed by nitrogenase that would not occur in the absence of N2.