Nitrite reductase (NO-forming)

In enzymology, a nitrite reductase (NO-forming) (EC 1.7.2.1) is an enzyme that catalyzes the chemical reaction

nitric oxide + H₂O + ferricytochrome c ⇌ nitrite + ferrocytochrome c + 2 H⁺

The 3 substrates of this enzyme are nitric oxide, H₂O, and ferricytochrome c, whereas its 3 products are nitrite, ferrocytochrome c, and H⁺.

This enzyme belongs to the family of oxidoreductases, specifically those acting on other nitrogenous compounds as donors with a cytochrome as acceptor. The systematic name of this enzyme class is nitric-oxide:ferricytochrome-c oxidoreductase. Other names in common use include cd-cytochrome nitrite reductase, [nitrite reductase (cytochrome)] [misleading, see comments.], cytochrome c-551:O2, NO2+ oxidoreductase, cytochrome cd, cytochrome cd1, hydroxylamine (acceptor) reductase, methyl viologen-nitrite reductase, nitrite reductase (cytochrome, and NO-forming). This enzyme participates in nitrogen metabolism. It has 3 cofactors: FAD, Iron, and Copper.

Structural studies

As of late 2007, 20 structures have been solved for this class of enzymes, with PDB accession codes 1RZP, 1RZQ, 1SJM, 1SNR, 1ZDQ, 1ZDS, 1ZV2, 2A3T, 2AVF, 2B08, 2BW4, 2BW5, 2BWD, 2BWI, 2DV6, 2DWS, 2DWT, 2DY2, 2FJS, and 2JFC.

References

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