Sharma, Umender K and Chatterji, Dipankar (2010) Transcriptional switching in Escherichia coli during stress and starvation by modulation of Sigma 70 activity. In: FEMS Microbiology Reviews, 34 (5). pp. 646-657.Full text not available from this repository.
During active growth of Escherichia coli, majority of the transcriptional activity is carried out by the housekeeping sigma factor (Sigma 70), whose association with core RNAP is generally favoured because of its higher intracellular level and higher affinity to core RNAP. In order to facilitate transcription by alternative sigma factors during nutrient starvation, the bacterial cell uses multiple strategies by which the transcriptional ability of Sigma 70 is diminished in a reversible manner. The facilitators of shifting the balance in favour of alternative sigma factors happen to be as diverse as a small molecule (p)ppGpp (represents ppGpp or pppGpp), proteins (DksA, Rsd) and a species of RNA (6S RNA). Although 6S RNA and (p)ppGpp were known in literature for a long time, their role in transcriptional switching has been understood only in recent years. With themelucidation of function of DksA, a new dimension has been added to the phenomenon of stringent response. As the final outcome of actions of (p)ppGpp, DksA, 6S RNA and Rsd is similar, there is a need to analyse hese mechanisms in a collective manner. We review the recent trends in understanding the regulation of Sigma 70 by (p)ppGpp, DksA, Rsd and 6S RNA and present a case for evolving a unified model of RNAP redistribution during starvation by modulation of Sigma 70 activity in E. coli.
|Item Type:||Journal Article|
|Additional Information:||Copyright of this article belongs to John Wiley & Sons.|
|Keywords:||transcription regulation;starvation;sigma factors;Sigma 70;(p)ppGpp;DksA;Rsd;6S RNA|
|Department/Centre:||Division of Biological Sciences > Molecular Biophysics Unit|
|Date Deposited:||23 Aug 2010 11:08|
|Last Modified:||23 Aug 2010 11:08|
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