Reaction: NH3 + 3 NAD+ + 2 H2O = nitrite + 3 NADH + 5 H+
Other name(s): nitrite reductase (reduced nicotinamide adenine dinucleotide); NADH-nitrite oxidoreductase; assimilatory nitrite reductase (ambiguous); nirB (gene name); nirD (gene name)
Systematic name: ammonia:NAD+ oxidoreductase
Comments: An iron-sulfur flavoprotein (FAD) containing siroheme. This prokaryotic enzyme is specific for NADH. In addition to catalysing the 6-electron reduction of nitrite to ammonia, the enzyme from Escherichia coli can also catalyse the 2-electron reduction of hydroxylamine to ammonia. cf. EC 1.7.1.4, nitrite reductase [NAD(P)H].
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:
References:
1. Vega, J.M., Guerrero, M.G., Leadbetter, E. and Losada, M. Reduced nicotinamide-adenine dinucleotide-nitrite reductase from Azotobacter chroococcum. Biochem. J. 133 (1973) 701-708. [PMID: 4147887]
2. Jackson, R.H., Cornish-Bowden, A. and Cole, J.A. Prosthetic groups of the NADH-dependent nitrite reductase from Escherichia coli K12. Biochem. J. 193 (1981) 861-867. [PMID: 7030314]
3. Cammack, R., Jackson, R.H., Cornish-Bowden, A. and Cole, J.A. Electron-spin-resonance studies of the NADH-dependent nitrite reductase from Escherichia coli K12. Biochem. J. 207 (1982) 333-339. [PMID: 6297458]
4. Harborne, N.R., Griffiths, L., Busby, S.J. and Cole, J.A. Transcriptional control, translation and function of the products of the five open reading frames of the Escherichia coli nir operon. Mol. Microbiol. 6 (1992) 2805-2813. [PMID: 1435259]