Function
Nitrate reductase plays a strong role in the nitrogen cycle. It fixes nitrate to nitrite so it can be more easily converted to nitrogen gas for the environment. [1] Nitrate reduction can also cause increases in the levels of phosphate in groundwater. [2] narG consists of 3 sub-units; G, H, and I. The G sub-unit contains the active site of narG while the other sub-units are involved in electron transport. The I sub-unit is also a membrane anchor protein. [3]
Relevance
Nitrates from agricultural runoff can pollute bodies of water and damage the ecosystem. When nitrate concentration increases in water sources, it leads to algal blooms and eutrophication which can drastically reduce the species diversity of the water source. [4] Mutations of narG can result in a reduced efficiency to fix nitrates to nitrogen. This could be a potential bioremediation pathway to study.
Structural highlights
in the G sub-unit, where nitrate is fixed to nitrite. The molybdenum molecule is responsible for nitrate reduction. The FS0 cluster is a potential electron transfer route for the molybdenum core. [5]
Molecules involved in are highlighted. The molecules involved include 3 heme groups and 5 iron-sulfur complexes. This electron transport chain helps maintain molybdenum's ability to fix nitrate. [6]
where mutations can occur that prevent the FS0 cluster from binding, specifically a mutation to .
has been mutated to a Serine. This can reduce enzyme efficiency by removal of the positive charge of Arginine.
