Abstract
A transcriptional fusion of a synthetic FNR-dependent promoter derived from Escherichia coli has been introduced into Paracoccus denitrificans on a broad-host-range plasmid. The patterns of expression of β-galactosidase from this fusion and from a control which is not regulated by FNR have been studied. The results indicate that P. denitrificans expresses a transcriptional regulator which has a very similar DNA-binding specificity to FNR, and responds to a similar physiological signal.