Role of Nitrogenase Enzyme

Role of Nitrogenase Enzyme:-

- Nodule contains nitrogenase and leghaemoglobin. 

- The nitrogenase has 2 components:

i. Molybdoferredoxin (Mo-Fe protein)

ii. Azoferredoxin (Fe-protein)

- The free di-nitrogen first bound to MoFe protein and is not released until completely reduced to ammonia. 

- In this process ferredoxin serves as an electron donor to Fe-protein (nitrogenase reductase) which in turn hydrolyzes ATP and reduce Mo-Fe protein, the Mo-Fe protein in Turn reduce the substrate N2. The electrons and ATP are provided by photosynthesis and respiration of the host cells.

- Many intermediates are formed to form ammonia (NH3).

Dinitrogen → Hydrazine → Diamine → Ammonia

- Ammonia (NH3) is immediately protonated at physiological pH to form ammonium ion (NH4+). As NH4+ is toxic to plants, it is rapidly used near the site of generation to synthesize amino acids.