Nitrite controls the release of nitric oxide in Pseudomonas aeruginosa cd1 nitrite reductase

Here we demonstrate for the first time that the physiological substrate nitrite displaces NO from the ferrous enzyme, which enters a new catalytic cycle; this reaction depends on the conserved His369 whose role in substrate stabilization is crucial for catalysis. Thus we suggest that also in vivo the activity of cd1NIR is controlled by nitrite.