The Ribosome: a Metabolite-Responsive Transcription Regulator

Stewart, Valley

doi:10.1128/jb.00604-08

Cited by 3 publications

(4 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Mechanisms of transcriptional control by translation have already been reported in E. coli . For mRNAs of some amino acid metabolic enzymes, ribosome deceleration leads to attenuation or antitermination of transcription [31,32]. In a more general way, ribosome acceleration and deceleration were shown to directly result in corresponding changes in speed of the RNA polymerase [33].…”

Section: Discussionmentioning

confidence: 99%

Bacterial translational regulations: high diversity between all mRNAs and major role in gene expression

et al. 2012

View full text Add to dashboard Cite

BackgroundIn bacteria, the weak correlations at the genome scale between mRNA and protein levels suggest that not all mRNAs are translated with the same efficiency. To experimentally explore mRNA translational level regulation at the systemic level, the detailed translational status (translatome) of all mRNAs was measured in the model bacterium Lactococcus lactis in exponential phase growth.ResultsResults demonstrated that only part of the entire population of each mRNA species was engaged in translation. For transcripts involved in translation, the polysome size reached a maximum of 18 ribosomes. The fraction of mRNA engaged in translation (ribosome occupancy) and ribosome density were not constant for all genes. This high degree of variability was analyzed by bioinformatics and statistical modeling in order to identify general rules of translational regulation. For most of the genes, the ribosome density was lower than the maximum value revealing major control of translation by initiation. Gene function was a major translational regulatory determinant. Both ribosome occupancy and ribosome density were particularly high for transcriptional regulators, demonstrating the positive role of translational regulation in the coordination of transcriptional networks. mRNA stability was a negative regulatory factor of ribosome occupancy and ribosome density, suggesting antagonistic regulation of translation and mRNA stability. Furthermore, ribosome occupancy was identified as a key component of intracellular protein levels underlining the importance of translational regulation.ConclusionsWe have determined, for the first time in a bacterium, the detailed translational status for all mRNAs present in the cell. We have demonstrated experimentally the high diversity of translational states allowing individual gene differentiation and the importance of translation-level regulation in the complex process linking gene expression to protein synthesis.

show abstract

Section: Discussionmentioning

confidence: 99%

Bacterial translational regulations: high diversity between all mRNAs and major role in gene expression

et al. 2012

View full text Add to dashboard Cite

show abstract

“…54 The PCR-amplified fragments of malQ and the tnaC regulatory element were ligated into the multiple cloning site of the modified pTrc99A plasmid by Gibson assembly to construct pMC. tnaC acts as the L-Trp sensor 55 to transform the signal of the intracellular L-Trp concentration into the expression of the downstream malQ. pTet was constructed by replacing malQ in pMC with tetA and adding dnaQ926 controlled by the pBAD promoter.…”

mentioning

confidence: 99%

Maltose Utilization as a Novel Selection Strategy for Continuous Evolution of Microbes with Enhanced Metabolite Production

Liu

Wang

et al. 2017

ACS Synth. Biol.

View full text Add to dashboard Cite

We have developed a novel selection circuit based on carbon source utilization that establishes and sustains growth-production coupling over several generations in a medium with maltose as the sole carbon source. In contrast to traditional antibiotic resistance-based circuits, we first proved that coupling of cell fitness to metabolite production by our circuit was more robust with a much lower escape risk even after many rounds of selection. We then applied the selection circuit to the optimization of L-tryptophan (l-Trp) production. We demonstrated that it enriched for specific mutants with increased l-Trp productivity regardless of whether it was applied to a small and defined mutational library or a relatively large and undefined one. From the latter, we identified four novel mutations with enhanced l-Trp output. Finally, we used it to select for several high l-Trp producers with randomly generated genome-wide mutations and obtained strains with up to 65% increased l-Trp production. This selection circuit provides new perspectives for the optimization of microbial cell factories for diverse metabolite production and the discovery of novel genotype-phenotype associations at the single-gene and whole-genome levels.

show abstract

“…Consequently, Rho does not bind to the transcript and the stalled RNA polymerase is not offloaded and continues to transcribe the downstream genes tnaA and tnaB (35)(36)(37)(38). Thus, tryptophan posttranscriptionally induces the expression from the tnaCAB operon in E. coli (79). The primary structure of the TnaC leader peptide as well as the nucleotide sequence of the boxA-rut site within the tnaCAB operon of EPEC and EHEC are identical to that of E. coli K-12, suggesting that tryptophan-mediated stimulation of the tna operon is likely conserved (Fig.…”

Section: Vol 193 2011mentioning

confidence: 99%

“…The nascent leader peptide, TnaC, while translocating through the exit tunnel of the ribosome, transduces conformational alterations in the ribosome to generate a stereospecific L-tryptophan-binding site near the peptidyltransferase center (79). Bound tryptophan promotes ribosomal stalling, which in turn masks the boxA-rut riboelement of the transcriptional terminator Rho that overlaps the C terminus as well as the segment immediately downstream of the tnaC open reading frame (ORF) (35,37,80).…”

Section: Vol 193 2011mentioning

confidence: 99%

CsrA and TnaB Coregulate Tryptophanase Activity To Promote Exotoxin-Induced Killing of Caenorhabditis elegansby Enteropathogenic Escherichia coli

2011

View full text Add to dashboard Cite

Enteropathogenic Escherichia coli (EPEC) requires the tnaA- encoded enzyme tryptophanase and its substrate tryptophan to synthesize diffusible exotoxins that kill the nematode Caenorhabditis elegans . Here, we demonstrate that the RNA-binding protein CsrA and the tryptophan permease TnaB coregulate tryptophanase activity, through mutually exclusive pathways, to stimulate toxin-mediated paralysis and killing of C. elegans .

show abstract

The Ribosome: a Metabolite-Responsive Transcription Regulator

Cited by 3 publications

References 53 publications

Bacterial translational regulations: high diversity between all mRNAs and major role in gene expression

Bacterial translational regulations: high diversity between all mRNAs and major role in gene expression

Maltose Utilization as a Novel Selection Strategy for Continuous Evolution of Microbes with Enhanced Metabolite Production

CsrA and TnaB Coregulate Tryptophanase Activity To Promote Exotoxin-Induced Killing of Caenorhabditis elegansby Enteropathogenic Escherichia coli

Contact Info

Product

Resources

About