Characterisation of the E. coli HMS and BLR host cell proteomes
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ABSTRACT: In this project, we characterise and compare the host cell proteomes of E. coli BLR(DE3) and E. coli HMS174(DE3) strains using shotgun proteomics.
Project description:Heat-responsive and time-resolved changes in transcriptome of E. coli BL21(DE3) Experimentally mapped transcriptome structure of Escherichia coli BL21(DE3) by hybridizing total RNA (including RNA species <200 nt) to genome-wide high-density tiling arrays (60 mer probes tiled every 10 nt).
Project description:We report the effect of oxygenation state in lactose grown escherichia coli producing recombinant proteins. To shed more light on the mechanistic correlation between the uptake of lactose and dissolved oxygen, a comprehensive study has been undertaken with the E. coli BL21 (DE3) strain. Differences in consumption pattern of lactose, metabolites, biomass and product formation due to aerobiosis have been investigated. Transcriptomic profiling of metabolic changes due to aerobic process and microaerobic process during protein formation phase has been studied and the results provide a deeper understanding of protein production in E. coli BL21 (DE3) strains with lactose based promoter expression systems.This study also provides a scientific understanding of escherichia coli metabolism upon oxygen fluctuations.
Project description:Different genetic engineering strategies have been proposed to obtain E. coli strains that selectively consume xylose. In this study, a previously reported strategy for obtaining a xylose-selective strain in E. coli K12 was applied to E. coli BL21 (DE3). While this approach resulted in the expected xylose-selective phenotype, a low xylose consumption rate was recorded when the strain was grown on a mixture of xylose and glucose. To enhance xylose consumption, a variant of the transcriptional activator XylR was expressed. The resulting strain not only exhibited an improved capacity to consume xylose but also slightly recovered the ability to consume glucose. The aim of the microarray analysis was to identify the transcriptional changes associated with glucose assimilation in the BL21(DE3) derived xylose-selective strain.
Project description:Experimentally mapped transcriptome structure of Escherichia coli BL21(DE3) by hybridizing total RNA (including RNA species <200 nt) to genome-wide high-density tiling arrays (60 mer probes tiled every 10 nt).
Project description:Whole genome sequencing was performed on E. coli BL21 (DE3) evolved at 25°C in pH 9 terrific broth media buffered with Tris-HCl (pH 9). The evolved E. coli was characterized and compared to the parent strain.
Project description:Deep-sequencing of the engineered production genes in five E coli production chassis strains (BL21(DE3), MG1655, TOP10, W and W3110) producing two case metabolic products, 2,3-butanediol and mevalonic acid
Project description:This transcription profiling time course experiment was conducted in order to analyze the cellular response of E. coli HMS174(DE3)-pET30a-sSpAD-GFPmut3.1-Strep to recombinant protein export to the periplasm. Three biological replicates were generated by using a carbon limited exponential fed-batch cultivation.
Project description:This transcription profiling time course experiment was conducted in order to analyze the cellular response of E. coli HMS174(DE3)-pET30a-GFPmut3.1-Strep to high level cytoplasmic protein expression. Three biological replicates were generated by using a carbon limited exponential fed-batch cultivation.
Project description:Calcium-activated potassium channels are important membrane proteins that help in maintaining the cellular physiology and cell signalling. Till date no Calcium-activated potassium channels have been identified in Leishmania donovani. It’s gene was cloned into pET vector and expressed in E. coli BL21 (DE3). The recombinant protein was purified using nickel affinity chromatography.
Project description:Purpose: We investigated the effect of the T4 MotB protein on E. coli gene expression Method: BL21(DE3) E. coli containing either pNW129 or pNW129-MotB were grown to early log phase (OD600 ~ 0.3) then induced with 0.2% arabinose for 20 minutes. Cells were then harvested and total RNA was isolated. The cDNA library was prepared using a modified RNATagSeq workflow as previously described (Shishkin, A.A. et al. 2015 Nat Methods). Optimum fragmentation of the total RNA samples in this library was determined to be 3 min at 94C in FastAP buffer (Thermo Fischer Scientific). The cDNA Library was run on a Bioanalyzer using the Agilent High Sensitivity DNA Kit to evaluate the quality of the library. The concentration of the cDNA library was determined by qPCR using the KAPA Library Quantification Kit (Kapa Biosystems, Wilmington, MA, USA) and CFX96 Real-Time PCR Detection System (Bio-Rad, Hercules, CA, USA). Sequencing was performed by the NIDDK Genomics Core facility using a MiSeq system with the single-end 50 bp Sequencing Kit (Illumina, San Diego, CA, USA). RNA-seq data was processed as previously described using E. coli B str. DE3 (NC_012971.2) as the reference genome. Differential expression between conditions was represented as a fold change, and genes with both a fold change ≥2 and adjusted p value ≤ 0.05 were considered significant. Results: RNA-seq data revealed that the expression of genes encoded in the cryptic prograge Lambda DE3 as well as an additional 29 of E. coli genes were significantly increased after motB expression. Conclusion: T4 MotB is a DNA binding protein that compacts host DNA and disrupts H-NS dependent repression.