Nitrogenase Enzyme: A Review

Biological nitrogen fixation is accomplished through the catalytic action of complex enzyme system known as nitrogenase and it is the only known family of enzymes which accomplishes this process. The strength of Nitrogen molecule is because of its N-N triple bond. To break nitrogen atoms requires breaking of all three chemical bonds. So Nitrogen fixation using nitrogenase requires rather large inputs of energy to drive the process. Nitrogenase consists of two major protein components, namely, dinitrogenase (MoFe-protein) and dinitrogenase reductase (Feprotein). Both components contain molybdenum (Mo) as well. The iron (Fe) and molybdenum (Mo) in dinitrogenase (MoFe-protein) are contained in a cofactor called MoFe-cofactor or MoFe-co.The nitrogenase proteins are denatured by exposure to oxygen (O2), they can only operate in an anaerobic environment. Only certain microorganisms can synthesize the nitrogenase enzyme. Some of these microbes are free-living in soils and water, while others occur in mutualisms with fungi or plants