Project description:A1501 aroA is a gene derived from Pseudomonas stutzeri A1501, encoding a class II glyphosate-tolerant EPSP synthase. To understand the effect of class II EPSP synthase to E. coli under glyphosate shock, we constructed the class II EPSP synthase-expressing plasmid pUC-A1501. And pUC18 is the empty vector used as a control.
Project description:Study of the mechanisms of RecB mutant terminus DNA loss in Escherichia coli. FX158: WT MG1655 FX35: recB- FX37: ruvAB- FX51: matP- MIC18: recB- sbcD- sbcC- MIC20: recB- ruvAB- MIC24: matP- recB- MIC25: recA- recB- MIC31: sbcB- sbcD- MIC34: recA- recD- MIC40: linear chromosome MIC41: linear chromosome recB- MIC42: matP- ftsKC- MIC43: matP- ftsKC- recB- MIC48: recA- Cells were grown in M9 minimal medium supplemented with 0.4 % glucose to exponential phase (0.2 OD 650 nm). Chromosomal DNA was extracted using the Sigma GenElute bacterial genomic DNA kit. 5 μg of DNA were used to generate a genomic library according to Illumina's protocol. The libraries and the sequencing were performed by the High-throughput Sequencing facility of the I2BC (http://www.i2bc.paris-saclay.fr/spip.php?article399&lang=en, CNRS, Gif-sur-Yvette, France). Genomic DNA libraries were made with the ‘Nextera DNA library preparation kit’ (Illumina) following the manufacturer’s recommendations. Library quality was assessed on an Agilent Bioanalyzer 2100, using an Agilent High Sensitivity DNA Kit (Agilent technologies). Libraries were pooled in equimolar proportions. 75 bp single reads were generated on an Illumina MiSeq instrument, using a MiSeq Reagent kit V2 (500 cycles) (Illumina), with an expected depth of 217X. An in-lab written MATLAB-based script was used to perform marker frequency analysis. Reads were aligned on the Escherichia coli K12 MG1655 genome using BWA software. Data were normalized by dividing uniquely mapping sequence reads by the total number of reads. Enrichment of uniquely mapping sequence reads in 1 kb non-overlapping windows were calculated and plotted against the chromosomal coordinates.
Project description:Deep mutational scanning can provide significant insights into the function of essential genes in bacteria. Here, we developed a high-throughput method for mutating essential genes of Escherichia coli in their native genetic context. We used Cas9-mediated recombineering to introduce a library of mutations, created by error-prone PCR, within a gene fragment on the genome using a single gRNA pre-validated for high efficiency. Tracking mutation frequency through deep sequencing revealed biases in the position and the number of the introduced mutations. We overcame these biases by increasing the homology arm length and blocking mismatch repair to achieve a mutation efficiency of 85% for non-essential genes and 55% for essential genes. These experiments also improved our understanding of poorly characterized recombineering process using dsDNA donors with single nucleotide changes. Finally, we applied our technology to target rpoB, the beta subunit of RNA polymerase, to study resistance against rifampicin. In a single experiment, we validate multiple biochemical and clinical observations made in the previous decades and provide insights into resistance compensation with the study of double mutants.
Project description:The experiment contains ChIP-seq data for Enterotoxigenic Escherichia coli strain H10407 transformed with plasmid pRGM9818. The strain was grown at 37 degrees in LB medium and crosslinked with 1 % (v/v) formaldehyde. After sonication, to break open cells and fragment DNA, immunoprecipitations were done using antibodies against MarA, MarR or the RNA polymerase sigma 70 subunit. Libraries were prepared using DNA remaining after immunoprecipitation. Note that the MarR immunoprecipitations were not successful but the data served as a useful control for non-specifically immunoprecipitated DNA sequences.
Project description:In this study we generated 5'P libraries in wt and RNAse III mutant strains, grown to exponential and stationary phases. Libraries that retain short RNA fragments were also generated in both growth phases. After sequencing by Illumina NextSeq 500 system, reads were mapped to E. coli genome NC_000913.3. By comparing the read start counts per position in the wt and mutant strain libraries we identified the cleavage sites of RNase III.
Project description:IrrE is a unique gene in Deinococcus, which is the switch of DNA repair and celluar surival network. Expressing IrrE enhanced the salt tolence in E. coli. To understand the effect of IrrE to E. coli during salt shock, we constructed the IrrE-expressing plasmid pMG1-IrrE. And pMG1 is the empty vector used as a control. The GroESL promoter was amplified from D. radiodurans R1 genomic DNA by PCR with proper primers. The PCR product was ligated into the T-cloning site of T-vector pMD18T, generating the plasmid pMG1.
Project description:These E. coli strains were grown with various signaling molecules and the expression profiles were determined. Keywords: addition of quorum and host hormone signals