nalD Encodes a Second Repressor of the mexAB-oprM Multidrug Efflux Operon of Pseudomonas aeruginosa
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چکیده
منابع مشابه
nalD encodes a second repressor of the mexAB-oprM multidrug efflux operon of Pseudomonas aeruginosa.
The Pseudomonas aeruginosa nalD gene encodes a TetR family repressor with homology to the SmeT and TtgR repressors of the smeDEF and ttgABC multidrug efflux systems of Stenotrophomonas maltophilia and Pseudomonas putida, respectively. A sequence upstream of mexAB-oprM and overlapping a second promoter for this efflux system was very similar to the SmeT and TtgR operator sequences, and NalD bind...
متن کاملThe mexR repressor of the mexAB-oprM multidrug efflux operon in Pseudomonas aeruginosa: characterization of mutations compromising activity.
Mutations in mexR yield a multidrug resistance phenotype in nalB mutants of Pseudomonas aeruginosa as a result of derepression of the mexAB-oprM multidrug efflux operon. MexR produced by several nalB strains carried single amino acid changes that compromised MexR stability or its ability to dimerize. Changes at residues L95 and R21, however, produced a stable MexR protein capable of dimerizatio...
متن کاملMutations in PA3574 (nalD) lead to increased MexAB-OprM expression and multidrug resistance in laboratory and clinical isolates of Pseudomonas aeruginosa.
Mutations in genes mexR and nalC have previously been shown to drive overexpression of the MexAB-OprM multidrug efflux system in Pseudomonas aeruginosa. A transposon insertion multidrug-resistant mutant of P. aeruginosa overproducing MexAB-OprM was disrupted in yet a third gene, PA3574, encoding a probable repressor of the TetR/AcrR family that we have dubbed NalD. Clinical strains overexpressi...
متن کاملSubstrate specificities of MexAB-OprM, MexCD-OprJ, and MexXY-oprM efflux pumps in Pseudomonas aeruginosa.
To find the exact substrate specificities of three species of tripartite efflux systems of Pseudomonas aeruginosa, MexAB-OprM, MexCD-OprJ, and MexXY-OprM, we constructed a series of isogenic mutants, each of which constitutively overproduced one of the three efflux systems and lacked the other two, and their isogenic mutants, which lacked all these systems. Comparison of the susceptibilities of...
متن کاملPentachlorophenol Induction of the Pseudomonas aeruginosa mexAB-oprM Efflux Operon: Involvement of Repressors NalC and MexR and the Antirepressor ArmR
Pentachlorophenol (PCP) induced expression of the NalC repressor-regulated PA3720-armR operon and the MexR repressor-controlled mexAB-oprM multidrug efflux operon of Pseudomonas aeruginosa. PCP's induction of PA3720-armR resulted from its direct modulation of NalC, the repressor's binding to PA3720-armR promoter-containing DNA as seen in electromobility shift assays (EMSAs) being obviated in th...
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ژورنال
عنوان ژورنال: Journal of Bacteriology
سال: 2006
ISSN: 0021-9193,1098-5530
DOI: 10.1128/jb.01342-06