Dataset Information

Use of a promiscuous, constitutively-active bacterial enhancer-binding protein to define the ??? (RpoN) regulon of Salmonella Typhimurium LT2.

ABSTRACT: Sigma54, or RpoN, is an alternative ? factor found widely in eubacteria. A significant complication in analysis of the global ??? regulon in a bacterium is that the ??? RNA polymerase holoenzyme requires interaction with an active bacterial enhancer-binding protein (bEBP) to initiate transcription at a ???-dependent promoter. Many bacteria possess multiple bEBPs, which are activated by diverse environmental stimuli. In this work, we assess the ability of a promiscuous, constitutively-active bEBP-the AAA+ ATPase domain of DctD from Sinorhizobium meliloti-to activate transcription from all ???-dependent promoters for the characterization of the ??? regulon of Salmonella Typhimurium LT2.The AAA+?ATPase domain of DctD was able to drive transcription from nearly all previously characterized or predicted ???-dependent promoters in Salmonella under a single condition. These promoters are controlled by a variety of native activators and, under the condition tested, are not transcribed in the absence of the DctD AAA+?ATPase domain. We also identified a novel ???-dependent promoter upstream of STM2939, a homolog of the cas1 component of a CRISPR system. ChIP-chip analysis revealed at least 70 ??? binding sites in the chromosome, of which 58% are located within coding sequences. Promoter-lacZ fusions with selected intragenic ??? binding sites suggest that many of these sites are capable of functioning as ???-dependent promoters.Since the DctD AAA + ATPase domain proved effective in activating transcription from the diverse ???-dependent promoters of the S. Typhimurium LT2 ??? regulon under a single growth condition, this approach is likely to be valuable for examining ??? regulons in other bacterial species. The S. Typhimurium ??? regulon included a high number of intragenic ??? binding sites/promoters, suggesting that ??? may have multiple regulatory roles beyond the initiation of transcription at the start of an operon.

SUBMITTER: Samuels DJ

PROVIDER: S-EPMC3844500 | biostudies-literature | 2013 Sep

REPOSITORIES: biostudies-literature

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Use of a promiscuous, constitutively-active bacterial enhancer-binding protein to define the σ⁵⁴ (RpoN) regulon of Salmonella Typhimurium LT2.

Samuels David J DJ Frye Jonathan G JG Porwollik Steffen S McClelland Michael M Mrázek Jan J Hoover Timothy R TR Karls Anna C AC

BMC genomics 20130905

<h4>Background</h4>Sigma54, or RpoN, is an alternative σ factor found widely in eubacteria. A significant complication in analysis of the global σ⁵⁴ regulon in a bacterium is that the σ⁵⁴ RNA polymerase holoenzyme requires interaction with an active bacterial enhancer-binding protein (bEBP) to initiate transcription at a σ⁵⁴-dependent promoter. Many bacteria possess multiple bEBPs, which are activated by diverse environmental stimuli. In this work, we assess the ability of a promiscuous, constit ...[more]

PMID: 24007446

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Dataset Information

Use of a promiscuous, constitutively-active bacterial enhancer-binding protein to define the ??? (RpoN) regulon of Salmonella Typhimurium LT2.

Publications

Use of a promiscuous, constitutively-active bacterial enhancer-binding protein to define the σ⁵⁴ (RpoN) regulon of Salmonella Typhimurium LT2.

Similar Datasets

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