EC - Nitric oxide reductase [NAD(P)+, nitrous oxide-forming]

  IntEnz view ENZYME view

IntEnz Enzyme Nomenclature


Accepted name:
nitric oxide reductase [NAD(P)+, nitrous oxide-forming]
Other names:
fungal nitric oxide reductase
cytochrome P450nor
NOR [ambiguous]
Systematic name:
nitrous oxide:NAD(P) oxidoreductase




A heme-thiolate protein (P450). The enzyme from Fusarium oxysporum utilizes only NADH, but the isozyme from Trichosporon cutaneum utilizes both NADH and NADPH. The electron transfer from NAD(P)H to heme occurs directly, not requiring flavin or other redox cofactors.

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB
Gene Ontology: GO:0102199


  1. Shoun, H., Tanimoto, T.
    Denitrification by the fungus Fusarium oxysporum and involvement of cytochrome P-450 in the respiratory nitrite reduction.
    J. Biol. Chem. 266 : 11078-11082 (1991). [PMID: 2040619]
  2. Shiro, Y., Fujii, M., Iizuka, T., Adachi, S., Tsukamoto, K., Nakahara, K., Shoun, H.
    Spectroscopic and kinetic studies on reaction of cytochrome P450nor with nitric oxide. Implication for its nitric oxide reduction mechanism.
    J. Biol. Chem. 270 : 1617-1623 (1995). [PMID: 7829493]
  3. Zhang, L., Kudo, T., Takaya, N., Shoun, H.
    The B' helix determines cytochrome P450nor specificity for the electron donors NADH and NADPH.
    J. Biol. Chem. 277 : 33842-33847 (2002). [PMID: 12105197]
  4. Oshima, R., Fushinobu, S., Su, F., Zhang, L., Takaya, N., Shoun, H.
    Structural evidence for direct hydride transfer from NADH to cytochrome P450nor.
    J. Mol. Biol. 342 : 207-217 (2004). [PMID: 15313618]

[EC created 2011]