Nitrate reductase structure, function and regulation: Bridging the gap between biochemistry and physiology

Authors

Wilbur H. Campbell, Michigan Technological University

Document Type

Article

Publication Date

1-1-1999

Abstract

Nitrate reductase (NR; EC 1.6.6.1-3) catalyzes NAD(P)H reduction of nitrate to nitrite. NR serves plants, algae, and fungi as a central point for integration of metabolism by governing flux of reduced nitrogen by several regulatory mechanisms. The NR monomer is composed of a ∼100-kD polypeptide and one each of FAD, heme-iron, and molybdenum-molybdopterin (Mo-MPT). NR has eight sequence segments: (a) N-terminal "acidic" region; (b) Mo-MPT domain with nitrate-reducing active site; (c) interface domain; (d) Hinge 1 containing serine phosphorylated in reversible activity regulation with inhibition by 14-3-3 binding protein; (e) cytochrome b domain; (f) Hinge 2; (g) FAD domain; and (h) NAD(P)H domain. The cytochrome b reductase fragment contains the active site where NAD(P)H transfers electrons to FAD. A complete three-dimensional dimeric NR structure model was built from structures of sulfite oxidase and cytochrome b reductase. Key active site residues have been investigated. NR structure, function, and regulation are now becoming understood.

Publication Title

Annual Review of Plant Biology

Recommended Citation

Campbell, W. (1999). Nitrate reductase structure, function and regulation: Bridging the gap between biochemistry and physiology. Annual Review of Plant Biology, 50, 277-303. http://doi.org/10.1146/annurev.arplant.50.1.277
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p/12617