| 12383513 |
Loprasert S, Sallabhan R, Whangsuk W, Mongkolsuk S: The Burkholderia pseudomallei oxyR gene: expression analysis and mutant characterization. Gene. 2002 Aug 21;296(1-2):161-9.
Burkholderia pseudomallei (Bp) is the causative agent of the life-threatening melioidosis in humans. The global transcription factor oxyR gene was isolated and characterized. It is located between recG, encoding a putative DNA helicase, and katG, encoding a putative catalase-peroxidase. oxyR is expressed as a monocistronic 1 kb mRNA and is induced by oxidative stress compounds. Northern, primer extension, and transcription reporter fusion analyses showed that oxyR mRNA is induced by 0.2 mM menadione, 2 mM paraquat, and 10 mM H (2) O (2). Two knockout mutants of oxyR were constructed, by single- and double-crossover recombination, and found to be hypersensitive to H (2) O (2) and paraquat. Bp lacking OxyR exhibited autoaggregation when cultured in liquid broth and an increased ability to form biofilms in minimal medium, but not in Luria-Bertani broth. The oxyR mutants also have a decreased level of extracellular protease activity. The altered phenotypes of oxyR deficient mutants were complemented when a copy of oxyR was transposed into the mutant chromosomes on the mini-Tn5 transposon. |
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