RT Journal Article SR Electronic(1) A1 Sánchez, Diego Germán A1 Primo, Emiliano David A1 Damiani, María Teresa A1 Lisa, Angela TeresitaYR 2017 T1 Pseudomonas aeruginosa gbdR gene is transcribed from a σ54-dependent promoter under the control of NtrC/CbrB, IHF and BetI JF Microbiology, VO 163 IS 9 SP 1343 OP 1354 DO https://doi.org/10.1099/mic.0.000502 PB Microbiology Society, SN 1465-2080, AB Pseudomonasaeruginosa uses choline as a source of carbon and nitrogen, and also for the synthesis of glycine betaine, an osmoprotectant under stress conditions such as drought and salinity. The transcription factor GbdR is the specific regulator of choline metabolism and it belongs to the Arac/XylS family of transcriptional regulators. Despite the link between choline catabolism and bacterial pathogenicity, gbdR regulation has not been explored in detail. In the present work, we describe how gbdR transcription can be initiated from a σ54-dependent promoter. gbdR transcription can be activated by NtrC in the absence of a preferential nitrogen source, by CbrB in the absence of a preferential carbon source, and by the integration host factor favouring DNA bending. In addition, we found that BetI negatively regulates gbdR expression in the absence of choline. We identified two overlapping BetI binding sites in the gbdR promoter sequence, providing an additional example of σ54-promoter down-regulation. Based on our findings, we propose a model for gdbR regulation and its impact on choline metabolism., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.000502