Nutrient acquisition is critical to survival and infection by the opportunistic bacterium Pseudomonas aeruginosa. This pathogen expresses a number of virulence factors that are a part of the starvation response and are important in host-pathogen interactions. Additionally, P. aeruginosa is resistant to a large number of antibiotics and has become difficult to treat once it has colonized a tissue. New pharmaceutical treatments are sought while the metabolism of this organism must be fully understood to select new targets for therapy. The leucine- responsive regulatory protein (Lrp) could be a promising target for treatment. The ortholog in Escherichia coli is a global regulator of metabolism and regulates many genes related to amino acid degradation, transport and synthesis. There are structural and functional similarities that indicate that Lrp in both species plays a similar role. In this study, the role of Lrp in P. aeruginosa was investigated using a microbial and molecular approach to determine if Lrp regulates more genes than the published single operon, dadRAX. The results of this study suggest that Lrp plays a role in regulating important virulence factors and growth patterns in both nutrient-rich and nutrient-poor media, and thus may act as a global regulator in the metabolism of P. aeruginosa
