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Polyphosphate binds to the principal sigma factor of RNA polymerase during starvation response in Helicobacter pylori.
- Source :
-
Molecular Microbiology . Aug2010, Vol. 77 Issue 3, p618-627. 10p. 1 Diagram, 4 Graphs. - Publication Year :
- 2010
-
Abstract
- Helicobacter pylori persists deep in the human gastric mucus layer in a harsh, nutrient-poor environment. Survival under these conditions depends on the ability of this human pathogen to invoke starvation/stress responses when needed. Unlike many bacteria, H. pylori lacks starvation/stress-responding alternative sigma factors, suggesting an additional mechanism might have evolved in this bacterium. Helicobacter pylori produces polyphosphate; however, the role and target of polyphosphate during starvation/stress have not been identified. Here we show that polyphosphate accumulated during nutrient starvation directly targets transcriptional machinery by binding to the principal sigma factor in H. pylori, uncovering a novel mechanism in microbial stress response. A positively charged Lys-rich region at the N-terminal domain of the major sigma factor is identified as the binding region for polyphosphate (region P) in vivo and in vitro, revealing a new element in sigma 70 family proteins. This interaction is biologically significant because mutant strains defective in the interaction undergo premature cell death during starvation. We suggested that polyphosphate is a second messenger employed by H. pylori to mediate gene expression during starvation/stress. The putative ‘region P’ is present in sigma factors of other human pathogens, suggesting that the uncovered interaction might be a general strategy employed by other pathogens. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 0950382X
- Volume :
- 77
- Issue :
- 3
- Database :
- Academic Search Index
- Journal :
- Molecular Microbiology
- Publication Type :
- Academic Journal
- Accession number :
- 52300864
- Full Text :
- https://doi.org/10.1111/j.1365-2958.2010.07233.x