Anaerobically induced expression of the nitrite reductase cytochrome c-551 operon from Pseudomonas aeruginosa

The nitrite reductase gene ( denA) and the cytochrome c-551 gene ( denB) are located only 50 bp apart from each other in the Pseudomonas aeruginosachromosome. We report evidence that these two genes are co-transcribed as an operon only under anaerobic (denitrifying) conditions. The nucleotide sequence of the promoter (regulatory) region of the operon is highly AT-rich and contains a sequence closely resembling the consensus FNR binding site in E. coli.