Nucleoid remodeling by an altered HU protein: Reorganization of the transcription program
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892-4264
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Contributed by Sankar Adhya, September 14, 2005
Abstract
Bacterial nucleoid organization is believed to have minimal influence on the global transcription program. Using an altered bacterial histone-like protein, HUα, we show that reorganization of the nucleoid configuration can dynamically modulate the cellular transcription pattern. The mutant protein transformed the loosely packed nucleoid into a densely condensed structure. The nucleoid compaction, coupled with increased global DNA supercoiling, generated radical changes in the morphology, physiology, and metabolism of wild-type K-12 Escherichia coli. Many constitutive housekeeping genes involved in nutrient utilization were repressed, whereas many quiescent genes associated with virulence were activated in the mutant. We propose that, as in eukaryotes, the nucleoid architecture dictates the global transcription profile and, consequently, the behavior pattern in bacteria.
Footnotes
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↵ * To whom correspondence should be addressed at: Laboratory of Molecular Biology, National Cancer Institute, 37 Convent Drive, Room 5106, Bethesda, MD 20892-4264. E-mail: sadhya{at}helix.nih.gov.
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Author contributions: S.K. and S.A. designed research; S.K. and R.E. performed research; S.K. and S.A. analyzed data; and S.K. wrote the paper.
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Conflict of interest statement: No conflicts declared.
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Abbreviation: IPTG, isopropyl β-d-thiogalactoside.
