Ontology highlight
ABSTRACT:
PROVIDER: PRJNA643582 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:In Escherichia coli, the heat shock protein 15 (Hsp15) is part of the cellular response to elevated temperature. Hsp15 interacts with peptidyl-tRNA-50S complexes that arise upon dissociation of translating 70S ribosomes, and is proposed to facilitate their rescue and recycling. A previous structure of E. coli Hsp15 in complex with peptidyl-tRNA-50S complex reported a binding site located at the central protuberance of the 50S subunit. By contrast, recent structures of RqcP, the Hsp15 homolog in Bacillus subtilis, in complex with peptidyl-tRNA-50S complexes have revealed a distinct site positioned between the anticodon-stem-loop (ASL) of the P-site tRNA and H69 of the 23S rRNA. Here we demonstrate that exposure of E. coli cells to heat shock leads to dissociation of 70S ribosomes and accumulation of 50S subunits, thus identifying a natural substrate for Hsp15 binding. Additionally, we have determined a cryo-EM reconstruction of the Hsp15-50S-peptidyl-tRNA complex isolated from heat shocked E. coli cells, revealing that Hsp15 binds to the 50S-peptidyl-tRNA complex analogously to its B. subtilis homolog RqcP. Collectively, our findings support a model where Hsp15 promotes access to the A-site for putative rescue factors to release the aberrant nascent polypeptide chain.
2022-11-15 | GSE216100 | GEO
Project description:RNA modifications have a substantial impact on tRNA function. While modifications in the anticodon loop play an important role in translational fidelity, modifications in the tRNA core influence tRNA structural stability. In bacteria, tRNA modifications play important roles in the stress response and expression of virulence factors. While tRNA modifications are well characterized in a few model organisms, our knowledge of tRNA modifications in human pathogens, such as Pseudomonas aeruginosa is lacking. Here we leveraged two orthogonal approaches to build a reference landscape of tRNA modifications in E. coli, which we used to identify tRNA modifications in P. aeruginosa. We determined conservation for many modifications between the two organisms. We also identified potential sites of tRNA modification in P. aeruginosa tRNA that are not present in E. coli. One of these sites is found at the same positions as acacp3U, a modification previously identified in Vibrio cholerae. Identifying which modifications are present on different tRNAs will uncover the pathways impacted by the different tRNA modifying enzymes, some of which may play roles in determining virulence and pathogenicity.
2024-04-03 | GSE236676 | GEO
Project description:Ribosome pauses are associated with diverse co-translational events and determine the fate of mRNAs and proteins. Thus the identification of the precise pause sites across transcriptome is a key, however, the landscape in bacterial has remained ambiguous. Here, we harnessed the multiple ribosome profiling strategies (standard, high-salt-wash, and disome) to survey the robust ribosome pause sites in E. coli. The found pause sites showed the correspondence with biochemical validation by integrated nascent chain profiling (iNP), which detects polypeptidyl-tRNA, an elongation intermediate. Among the list, ribosome pause at Asn586 of ycbZ was ensured by biochemical reporter assay, tRNA-seq, and cryo-electron microscopy. Our results provide a useful resource of ribosome stalling sites in bacteria.
2021-11-23 | GSE180482 | GEO
Project description:Mature tRNA pools were measured using an adaptation of YAMAT-seq (Shigematsu et al., 2017; doi:10.1093/nar/gkx005 ) and further described in (Ayan et al., 2020; doi:10.7554/eLife.57947) in 10 strain-medium combinations (all strains dervied from the model bacterium E. coli MG1655). The aim of the experiment was to investigate the effect of reducing tRNA gene copy number on mature tRNA pools in rich and poor media.
2022-12-02 | GSE198606 | GEO
Project description:Bacterial RNA has emerged as important activator of innate immune responses by stimulating the endosomal Toll-like receptors TLR7 and TLR8 in humans. Guanosine 2’-O-methylation at position 18 (Gm18) in bacterial tRNA was shown to antagonize tRNA induced TLR7/8 activation, giving rise to a potential role of this modification as immune escape mechanism. This modification also occurs in eukaryotic tRNA, yet a physiological immune function remains to be established. We therefore set out to investigate the physiological role of Gm18 in prokaryotic and eukaryotic microorganisms by using mutants deficient in the respective 2’-O-methyltransferase. In E. coli, lack of 2’-O-methyltransferase trmH enhanced immune stimulatory properties of both tRNA and whole cellular RNA. Yet, when using living microorganisms, trmH mutants did not differ from their wildtype counterparts in terms of immunostimulation although gene expression profiling demonstrated the induction of a TLR8/RNA dependent gene signature by E. coli in principle. In summary, the results demonstrate that Gm18 is a global immune inhibitory RNA modification across the kingdoms and contributes to RNA recognition by innate immune cells.
2019-03-15 | GSE125797 | GEO
Project description:tRNAs are heavily decorated with post-transcriptional modifications (tRNA modifications). Profile of tRNA modifications in non-model organisms are largely uncharacterized. Here using high-throughput sequencing, sites and frequency of tRNA modifications are predicted in Vibrio cholerae and Escherichia coli. During cDNA synthesis, some modifications cause misincorporation of a wrong base or termination of reverse transcription (RT). Using these RT-derived signatures we aim to explore organism-specific modifications and to track changes in modification frequency among different cellular conditions.
2020-05-15 | GSE147614 | GEO
Project description:we report the identification and sequences of the tRNAome of industrially relevant microorganism Lactococcus lactis Three Next Generation sequencing runs annotated as S1, S2 and S3 were performed. Cells were harvested at exponential phase and tRNA was isolated. S1 and S2 were spiked with Phe-tRNAGAA from yeast and Lys-tRNAUUU from E. coli prior to cell lysis. S3 was spiked with Phe-tRNAGAA from yeast and Lys-tRNAUUU from E. coli before the library preparation to estimate the possible loss of tRNA in the extraction process.
2014-07-29 | E-GEOD-55392 | biostudies-arrayexpress
Project description:Ribosome pauses are associated with diverse co-translational events and determine the fate of mRNAs and proteins. Thus the identification of the precise pause sites across transcriptome is a key, however, the landscape in bacterial has remained ambiguous. Here, we harnessed the multiple ribosome profiling strategies (standard, high-salt-wash, and disome) to survey the robust ribosome pause sites in E. coli. The found pause sites showed the correspondence with biochemical validation by integrated nascent chain profiling (iNP), which detects polypeptidyl-tRNA, an elongation intermediate. Among the list, ribosome pause at Asn586 of ycbZ was ensured by biochemical reporter assay, tRNA-seq, and cryo-electron microscopy. Our results provide a useful resource of ribosome stalling sites in bacteria.
2021-11-23 | GSE160623 | GEO
Project description:Abstract: tRNAs are highly modified in the elbow region and harbor 5-methyluridine at position 54 and pseudouridine at position 55 in the T arm, which are generated by the enzymes TrmA and TruB, respectively. Although all elongator tRNAs contain these modifications across all domains of life, the cellular relevance of these modifications and their corresponding modifying enzymes remains elusive. In addition to modifying every tRNA, Escherichia coli TrmA and TruB have both been shown to fold tRNA independently of its modification activity acting as tRNA chaperones, and strains lacking trmA or truB are outcompeted by wildtype. To identify how TrmA and TruB contribute to cellular fitness, we have systematically assessed the effects of deleting trmA and/or trmB in E. coli. Since tRNA folding is a pre-requisite for tRNA aminoacylation, we determined cellular aminoacylation levels revealing a global decrease in aminoacylation for all tRNAs in ΔtrmA and ΔtruB. Moreover, the absence of 5-methyluridine 54 or pseudouridine 55 alters tRNA modification at other positions: whereas acp3U47 is decreased, thiouridine levels are increased. Understanding the importance of TrmA and TruB for tRNA aminoacylation and modification, we then analyzed how these global tRNA changes in ΔtrmA and ΔtruB strains affect translation. Whereas global protein synthesis is not significantly changed in ΔtrmA and ΔtruB, the abundances of many specific proteins are altered, and transcriptomics experiments suggest that the dysregulation of many proteins is controlled at the translational level. In conclusion, we demonstrate that universally conserved modifications of the tRNA elbow are critical for global tRNA function by enhancing other tRNA modifications, tRNA folding, tRNA aminoacylation and translation of specific genes thereby contributing to cellular fitness.
2023-05-31 | GSE233667 | GEO
Project description:These data represent the ratios of charged to total tRNA for E. coli auxotrophic strain CP78 during starvation for leucine over a time course of 32 minutes.
2010-05-27 | E-GEOD-2065 | biostudies-arrayexpress