Antibiotic-Dependent Induction of Pseudomonas putida DOT-T1E TtgABC Efflux Pump Is Mediated by the Drug Binding Repressor TtgR
AUTOR(ES)
Terán, Wilson
FONTE
American Society for Microbiology
RESUMO
Pseudomonas putida is well known for its metabolic capabilities, but recently, it has been shown to exhibit resistance to a wide range of antibiotics. In P. putida DOT-T1E, the TtgABC efflux pump, which has a broad substrate specificity, extrudes antibiotics such as ampicillin, carbenicillin, tetracycline, nalidixic acid, and chloramphenicol. We have analyzed the expression of the ttgABC efflux pump operon and its regulatory gene, ttgR, in response to several structurally unrelated antibiotics at the transcriptional level and investigated the role of the TtgR protein in this process. ttgABC and ttgR are expressed in vivo at a moderate basal level, which increases in the presence of hydrophobic antibiotics like chloramphenicol and tetracycline. In vitro experiments show that, in the absence of inducers, TtgR binds to a palindromic operator site which overlaps both ttgABC and ttgR promoters and dissociates from it in the presence of chloramphenicol and tetracycline. These results suggest that the TtgR repressor is able to bind to structurally different antibiotics, which allows induction of TtgABC multidrug efflux pump expression in response to these antimicrobial agents. This is the first case in which the expression of a drug transporter of the resistance-nodulation-division family has been shown to be regulated directly by antibiotics.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=201152Documentos Relacionados
- Efflux Pumps Involved in Toluene Tolerance in Pseudomonas putida DOT-T1E
- Three Efflux Pumps Are Required To Provide Efficient Tolerance to Toluene in Pseudomonas putida DOT-T1E
- Physiological Characterization of Pseudomonas putida DOT-T1E Tolerance to p-Hydroxybenzoate
- A Set of Genes Encoding a Second Toluene Efflux System in Pseudomonas putida DOT-T1E Is Linked to the tod Genes for Toluene Metabolism
- Involvement of the cis/trans Isomerase Cti in Solvent Resistance of Pseudomonas putida DOT-T1E