Role of Fnr1 and Fnr3 in transcriptional regulation under oxygen limitation in Herbaspirillum seropedicae

To determine the direct promoter targets of Fnr proteins, we correlated transcriptional changes observed in single fnr1 and fnr3 mutants (E-MTAB-5741) with ChIP-Seq analysis, taking advantage of C-terminally 3xFlag fnr alleles engineered into the H. seropedicae genome. ChIP-seq data were obtained from cultures grown under limited oxygen availability. Using this approach, DNA-binding targets for the H. seropedicae Fnr1 and Fnr3 proteins were unambiguously revealed and correlated with transcript profiles to determine the specific regulons of each protein.