論文 - 詳細
| RRC ID | 70553 |
|---|---|
| 著者 | Shimada T, Furuhata S, Ishihama A. |
| タイトル | Whole set of constitutive promoters for RpoN sigma factor and the regulatory role of its enhancer protein NtrC in Escherichia coli K-12. |
| ジャーナル | Microb Genom |
| Abstract |
The promoter selectivity of
Escherichia coli
RNA polymerase (RNAP) is determined by its promoter-recognition sigma subunit. The model prokaryote
E. coli
K-12 contains seven species of the sigma subunit, each recognizing a specific set of promoters. Using genomic SELEX (gSELEX) screening in vitro, we identified the whole set of ‘constitutive’ promoters recognized by the reconstituted RNAP holoenzyme alone, containing RpoD (σ70), RpoS (σ38), RpoH (σ32), RpoF (σ28) or RpoE (σ24), in the absence of other supporting regulatory factors. In contrast, RpoN sigma (σ54), involved in expression of nitrogen-related genes and also other cellular functions, requires an enhancer (or activator) protein, such as NtrC, for transcription initiation. In this study, a series of gSELEX screenings were performed to search for promoters recognized by the RpoN RNAP holoenzyme in the presence and absence of the major nitrogen response enhancer NtrC, the best-characterized enhancer. Based on the RpoN holoenzyme-binding sites, a total of 44 to 61 putative promoters were identified, which were recognized by the RpoN holoenzyme alone. In the presence of the enhancer NtrC, the recognition target increased to 61–81 promoters. Consensus sequences of promoters recognized by RpoN holoenzyme in the absence and presence of NtrC were determined. The promoter activity of a set of NtrC-dependent and -independent RpoN promoters was verified in vivo under nitrogen starvation, in the presence and absence of RpoN and/or NtrC. The promoter activity of some RpoN-recognized promoters increased in the absence of RpoN or NtrC, supporting the concept that the promoter-bound NtrC-enhanced RpoN holoenzyme functions as a repressor against RpoD holoenzyme. Based on our findings, we propose a model in which the RpoN holoenzyme fulfils the dual role of repressor and transcriptase for the same set of genes. We also propose that the promoter recognized by RpoN holoenzyme in the absence of enhancers is the ‘repressive’ promoter. The presence of high-level RpoN sigma in growing
E. coli
K-12 in rich medium may be related to the repression role of a set of genes needed for the utilization of ammonia as a nitrogen source in poor media. The list of newly identified regulatory targets of RpoN provides insight into
E. coli
survival under nitrogen-depleted conditions in nature. |
| 巻・号 | 7(11) |
| 公開日 | 2021-11-1 |
| DOI | 10.1099/mgen.0.000653 |
| PMID | 34787538 |
| PMC | PMC8743547 |
| MeSH | Bacterial Proteins / genetics Bacterial Proteins / metabolism Enhancer Elements, Genetic Escherichia coli Escherichia coli K12* / genetics Escherichia coli K12* / metabolism Escherichia coli Proteins PII Nitrogen Regulatory Proteins / metabolism Promoter Regions, Genetic RNA Polymerase Sigma 54 Sigma Factor* / genetics Sigma Factor* / metabolism Transcription Factors / genetics |
| IF | 4.853 |
| オルトメトリクス指標 |
オルトメトリクス指標項目
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| 最多言及媒体 | News |
| 各媒体での言及数の合計 | 1 |
| 過去6か月間でのオルトメトリクス指標の変動値 | 0.0 |
| リソース情報 | |
| 原核生物(大腸菌) | BW25113 JW3169 JW3839 |