title: Fumarate and nitrate reduction (FNR) dependent activation of the Escherichia coli anaerobic ribonucleotide reductase nrdDG promoter.
abstract: The nrdDG promoter regulates transcriptional expression of the anaerobic ribonucleotide reductase of Escherichia coli, an essential enzyme required to supply the building blocks for DNA synthesis. In this work, binding of the pleiotropic FNR (fumarate and nitrate reduction) transcriptional regulator to the nrdDG promoter region and the effects of binding on transcription were investigated. Gel retardation analysis with purified FNR* demonstrated FNR interaction at two FNR sites, termed FNR-2 and FNR-1, while studies with altered FNR boxes indicated that the upstream FNR-2 site was essential for anaerobic activation of the nrdDG promoter. Although the FNR-1 site was not absolutely required, it allowed maximal expression of this promoter. These results suggest that the two sites have an additive effect in coordinating nrdDG expression in response to shifting oxygen concentrations.
authors.affiliation: Institute of Biotechnology and Biomedicine, Department of Genetics and Microbiology, Autonomous University of Barcelona, Bellaterra, Spain.
authors.forename: Ignasi
authors.initials: I
authors.lastname: Roca
authors.forename: Ester
authors.initials: E
authors.lastname: Ballana
authors.forename: Anaïs
authors.initials: A
authors.lastname: Panosa
authors.forename: Eduard
authors.initials: E
authors.lastname: Torrents
authors.forename: Isidre
authors.initials: I
authors.lastname: Gibert
mesh_terms: D000693:Anaerobiosis; D001483:Base Sequence; D004268:DNA-Binding Proteins; D048168:Escherichia coli K12 / Q000201:enzymology / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D007506:Iron-Sulfur Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000235:genetics; D012264:Ribonucleotide Reductases / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C060704:FNR protein, E coli; D007506:Iron-Sulfur Proteins; D014157:Transcription Factors; C490362:NrdG protein, E coli; D012264:Ribonucleotide Reductases; C101141:anaerobic ribonucleotide reductase