Q9
Single choice
A research laboratory is investigating the quorum sensing system in Pseudomonas aeruginosa. They identify a novel autoinducer molecule and a corresponding transcriptional regulator. Disruption of the gene encoding this regulator leads to a significant decrease in the production of virulence factors such as elastase and pyocyanin. Further analysis reveals that this regulator directly binds to the promoter regions of these virulence genes in the presence of the autoinducer. This regulatory mechanism is an example of: