Rv3133c/dosR is a transcription factor that mediates the hypoxic response of Mycobacterium tuberculosis
Summary Unlike many pathogens that are overtly harmful to their hosts, Mycobacterium tuberculosis can persist for years within humans in a clinically latent state. Latency is often linked to hypoxic conditions within the host. Among M. tuberculosis genes induced by hypoxia is a putative transcriptio...
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Veröffentlicht in: | Molecular microbiology 2003-05, Vol.48 (3), p.833-843 |
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Sprache: | eng |
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Unlike many pathogens that are overtly harmful to their hosts, Mycobacterium tuberculosis can persist for years within humans in a clinically latent state. Latency is often linked to hypoxic conditions within the host. Among M. tuberculosis genes induced by hypoxia is a putative transcription factor, Rv3133c/DosR. We performed targeted disruption of this locus followed by transcriptome analysis of wild‐type and mutant bacilli. Nearly all the genes powerfully regulated by hypoxia require Rv3133c/DosR for their induction. Computer analysis identified a consensus motif, a variant of which is located upstream of nearly all M. tuberculosis genes rapidly induced by hypoxia. Further, Rv3133c/DosR binds to the two copies of this motif upstream of the hypoxic response gene alpha‐crystallin. Mutations within the binding sites abolish both Rv3133c/DosR binding as well as hypoxic induction of a downstream reporter gene. Also, mutation experiments with Rv3133c/DosR confirmed sequence‐based predictions that the C‐terminus is responsible for DNA binding and that the aspartate at position 54 is essential for function. Together, these results demonstrate that Rv3133c/DosR is a transcription factor of the two‐component response regulator class, and that it is the primary mediator of a hypoxic signal within M. tuberculosis. |
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ISSN: | 0950-382X 1365-2958 |
DOI: | 10.1046/j.1365-2958.2003.03474.x |