This reaction is critical for the production of protein in most crop plants, as nitrate is the predominant source of nitrogen in fertilized soils.

[3] The active site of these enzymes is a molybdenum ion that is bound to the four thiolate functional groups of two pterin molecules.

The coordination sphere of the molybdenum ion is completed by one amino-acid side chain and oxygen and/or sulfur ligands.

It can substitute for the NRA enzyme in Escherichia coli, allowing it to use nitrate as an electron acceptor for anaerobic respiration.

[7] A transmembrane nitrate reductase that can function as a proton pump (similar to the case of anaerobic respiration) has been discovered in the diatom Thalassiosira weissflogii.

The Mo(VI) double bond to oxygen is reduced by NAD(P)H passed through the intramolecular transport chain.

[14] Higher plants and some algae post-translationally regulate NR by phosphorylation of serine residues and subsequent binding of a 14-3-3 protein.

These studies found that nitrate reductase, in anoxic conditions improves the plants tolerance to being less aerated.