DpsA protects the human pathogen Burkholderia pseudomallei against organic hydroperoxide

Author: Loprasert Suvit  

Publisher: Springer Publishing Company

ISSN: 0302-8933

Source: Archives of Microbiology, Vol.182, Iss.1, 2004-09, pp. : 96-101

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Abstract

The human pathogen, Burkholderia pseudomalle</i>, is able to survive and multiply in hostile environments such as within macrophages. In an attempt to understand its strategy to cope with oxidative stress, the physiological role and gene regulation of a nonspecific DNA-binding protein (DpsA) was investigated. Expression of dpsA</i> increases in response to oxidative stress through increased transcription from the upstream katG</i> (catalase–peroxidase) promoter, which is OxyR dependent. dpsA</i> is also transcribed from its own promoter, which is activated by osmotic stress in an OxyR-independent manner. DpsA-deficient mutants are hypersensitive to tert</i>-butyl hydroperoxide, while overexpression of DpsA leads to increased resistance to organic oxidants. B. pseudomallei</i> DpsA can also protect Escherichia coli</i> against organic hydroperoxide toxicity. The mechanism of DpsA-mediated resistance to organic hydroperoxides was shown to differ from that of alkyl hydroperoxide reductase.