Functional, biochemical and genetic diversity of prokaryotic nitrate reductases

• Published in: Cellular and molecular life sciences : CMLS Vol. 58; no. 2; pp. 165 - 178
• Main Authors: Richardson, D J, Berks, B C, Russell, D A, Spiro, S, Taylor, C J
• Format: Journal Article
• Language: English
• Published: Switzerland Springer Nature B.V 01-02-2001; Birkhäuser Verlag
• Subjects: Amino Acid Sequence; Anaerobic respiration; Archaea - enzymology; Archaea - genetics; Azotobacter vinelandii - enzymology; Azotobacter vinelandii - genetics; Bacillus subtilis - enzymology; Bacillus subtilis - genetics; Bacteria; Biochemistry; Cyanobacteria - enzymology; Cyanobacteria - genetics; Denitrification; Energy dissipation; Enzymes; Evolution, Molecular; Genes, Archaeal; Genes, Bacterial; Genetic diversity; Genetic Variation; Klebsiella - enzymology; Klebsiella - genetics; Molecular Sequence Data; Multigene Family; Nitrate Reductase; Nitrate Reductases - chemistry; Nitrate Reductases - genetics; Nitrate Reductases - metabolism; Nitrate reduction; Nitrates; Paracoccus - enzymology; Paracoccus - genetics; Prokaryotes; Prokaryotic Cells - enzymology; Protein Subunits; Sequence Homology, Amino Acid
• ISSN: 1420-682X; 1420-9071
• DOI: 10.1007/pl00000845

Prokaryotic nitrate reduction can serve a number of physiological roles and can be catalysed by a number of biochemically distinct nitrate reductases. Three distinct nitrate reductase classes can be indentified in prokaryotes, NAS, NAR and NAP. NAS is located in the cytoplasmic compartment and participates in nitrogen assimilation. NAR is usually a three-subunit complex anchored to the cytoplasmic face of the membrane with its active site located in the cytoplasmic compartment and is involved in anaerobic nitrate respiration. NAP is a two-subunit complex, located in the periplasmic compartment, that is coupled to quinol oxidation via a membrane anchored tetraheme cytochrome. It shows considerable functional flexibility by participating in anaerobic respiration or redox energy dissipation depending on the organism in which it is found. The members of all three classes of enzymes bind the bis-molybdopterin guanine dinucleotide cofactor at the active site, but they differ markedly in the number and nature of cofactors used to transfer electrons to this site. Analysis of prokaryotic genome sequences available at the time of writing reveals that the different nitrate reductases are phylogenetically widespread.