The homeostasis of the pyridine nucleotide pool [NAD(P)H and NAD(P) + ] is maintained in Rhodobacter sphaeroides mutant strains defective in the cytochrome bc1 complex or the cytochrome c oxidases in terms of its concentration and redox state. Aerobic derepression of the puf operon, which is under the control of the PrrBA two-component system, in the CBB3 mutant strain of R. sphaeroides was shown to be not the result of changes in the redox state of the pyridine nucleotides and the

more »

... iquinol pool. Using the bc1 complex knock-out mutant strain of R. sphaeroides, we clearly demonstrated that the inhibitory effect of cbb3 oxidase on spectral complex formation is not caused indirectly by the redox change of the ubiquinone/ubiquinol pool.