Fig. 3.

Transcription of RNR genes in response to inhibitor treatment. Class II RNR (nrdJ) (A) and class I RNR (nrdA) (B) P. aeruginosa cultures with an optical density of 0.15 were treated with RNR inhibitors with antibacterial activities (streptonigrin, □; toluidine blue, ○; NSC228155, ■; NSC361666, thick black line) or DMSO as a control (△), and the fold-change in mRNA expression was monitored over time by real-time PCR. Whereas streptonigrin and toluidine blue lead to >10-fold changes in transcript levels of nrdJ, changes by NSC228155 and NSC361666 are modest and close to the control. None of the inhibitors significantly affected transcription of the nrdA gene.