A reappraisal of the nitric oxide-binding protein of denitrifying Pseudomonas.

The data presented by Rowe et al. [Biochem. Biophys. Res. Commun. 77, 253–258 (1977)] as evidence for a nitric oxide-binding protein in denitrifying Pseudomonas aeruginosa, are the result of a physiologically significant redox transition in the nitrite-reducing system and apparently do not indicate the functioning of such an auxiliary protein for denitrification. Nitrite reductase of this bacterium was identified as cytochrome cd which reduced nitrite to nitric oxide at the expense of electrons supplied by ascorbate-phenazine methosulfate.