ACTIVATION OF A CONSENSUS FNR-DEPENDENT PROMOTER BY DNR OF PSEUDOMONAS-AERUGINOSA IN RESPONSE TO NITRITE

Expression of the enzymes for anaerobic nitrate respiration of Pseudom onas aeruginosa requires two CRP/FNR-related transcriptional regulator s, ANR and DNR. Activity of the consensus CRP- or FNR-dependent promot er in the anr and dnr deficient mutants was investigated. The CRP-depe ndent promoter was active in the mutant strains. Both regulators could activate the promoter with a consensus FNR-binding motif. DNR-depende nt activation was nitrite-dependent, whereas activation by ANR was not , suggesting that only DNR is involved in sensing nitrogen oxides. (C) 1998 Federation of European Microbiological Societies. Published by E lsevier Science B.V. All rights reserved.