Novel physiological modulation of the Pu promoter of TOL plasmid: negative regulatory role of the TurA protein of Pseudomonas putida in the response to suboptimal growth temperatures.

From crude protein extracts of Pseudomonas putida KT2440, we identified a small protein, TurA, able to bind to DNA fragments bearing the entire Pu promoter sequence of the TOL plasmid. The knock-out inactivation of the turA gene resulted in enhanced transcription initiation from the Pu promoter, initially suggesting a negative regulatory role of TurA on Pu expression. Ectopic expression of TurA both in P.