METALS IN THE NITROGENASES

The current state of biological and biochemical research into the structure and function of nitrogenases is discussed. It is shown that there is considerable understanding of how nitrogenase systems based on Mo and Fe, V and Fe, and Fe only, are constituted and function. Surprisingly, the recent X-ray crystal-structure determinations of the Mo-nitrogenase proteins has done little to clarify the mechanism of dinitrogen reduction at the atomic level. The chemistry of dinitrogen complexes of Mo, V and Fe is reviewed briefly, and some of the problems concerning the structure of the centre at which dinitrogen is bound and reduced, and which remain to be resolved are presented.