ABSTRACT: We performed targeted metabolomics in Escherichia coli mutants to measure changes in levels of metabolites from glycolysis and citric acid cycle.
Project description:We performed targeted metabolomics in Escherichia coli mutants to measure changes in levels of metabolites from glycolysis and citric acid cycle.
Project description:We performed two dimensional thermal proteome profiling (2D-TPP) in Escherichia coli mutants to measure changes in abundance and thermal stability.
Project description:YbjN, an enterobacteria-specific protein, is a multicopy suppressor of ts9 temperature sensitivity in Escherichia coli. Microarray study revealed that the expression level of ybjN was inversely correlated with the expression of flagellar, fimbrial and acid resistance genes. Over-expression of ybjN significantly down-regulated genes involved in the citric acid cycle, glycolysis, the glyoxylate shunt, oxidative phosphorylation, and amino acid and nucleotide metabolism. On the other hand, over-expression of ybjN up-regulated toxin-antitoxin modules, the SOS responsive pathway, cold shock proteins and starvation-induced transporter genes. Our results collectively suggest that YbjN may play important roles in regulating bacterial multicellular behaviors, metabolism and survival under various stress conditions in Es. coli.
Project description:YbjN, an enterobacteria-specific protein, is a multicopy suppressor of ts9 temperature sensitivity in Escherichia coli. Microarray study revealed that the expression level of ybjN was inversely correlated with the expression of flagellar, fimbrial and acid resistance genes. Over-expression of ybjN significantly down-regulated genes involved in the citric acid cycle, glycolysis, the glyoxylate shunt, oxidative phosphorylation, and amino acid and nucleotide metabolism. On the other hand, over-expression of ybjN up-regulated toxin-antitoxin modules, the SOS responsive pathway, cold shock proteins and starvation-induced transporter genes. Our results collectively suggest that YbjN may play important roles in regulating bacterial multicellular behaviors, metabolism and survival under various stress conditions in Es. coli. A total of 8 samples were analyzed: E. coli wild type strain (2 replicates); E. coli ybjN mutant strain (3 replicates); E. coli ybjN over-expression strain (3 replicates).
Project description:Tpx, FolX and WrbA were identified as a targets for type 3 secretion inhibititors in pull-down assays.The transcriptional profile of Escherichia coli O157:H7 and isogenic mutants grown in MEM-HEPES were determined.
Project description:Inorganic polyphosphate (Poly P) is a polymer of various phosphate residues linked by phosphoanhydride bonds as in ATP. It is found in all cells in nature with roles in the origin and survival of species, particularly in bacteria. To study the role of the inorganic polyphosphate in bacteria, we obtained knockout mutants of polyP metabolism genes in Escherichia coli K12. We performed DNA microarray experiments of single mutants in polyphosphate kinase 1 (PPK1), exopolyphosphatase (PPX) and also with the double mutant (PPK1 and PPX). The mutant strains growth normally in LB medium but have different colony morphology phenotypes. All mutants have flagellation problems and a detail description of all gain and lost phenotypes o these strains will be published soon because we performed a complete phenotypic microarray study of all three mutant strains.
Project description:The carbon storage regulator A (CsrA) is a conserved swivel of a global regulatory system known to regulate central carbon pathways, biofilm formation, motility, and pathogenicity. The aim of this study was to characterize changes in major metabolic pathways induced by CsrA in the human enteropathogenic Escherichia coli (EPEC) strain E2348/69. The EPEC strain E2348/69 and a csrA deletion mutant were grown under virulence factor inducing conditions and characterized by a combined analysis of their metabolomes and transcriptomes. Of the 159 metabolites identified from untargeted GC/MS and LC/MS data, 70 were significantly (fold change ≥ 1.5; p-value ≤ 0.05) regulated between the knockout and the wildtype strain. A lack of csrA led to an upregulation of upper glycolysis and glycogen synthesis pathways, whereas lower glycolysis and the citric acid cycle were downregulated. Associated pathways from the citric acid cycle like aromatic amino acid and siderophore biosynthesis were also negatively influenced. The nucleoside salvage pathways were featured by an accumulation of nucleosides and nucleobases, and a downregulation of nucleotides. In addition, a pronounced downregulation of lyso-lipid metabolites was observed. A drastic change in the morphology in the form of vesicle-like structures of the csrA knockout strain was visible by electron microscopy, which is supposed to be a consequence of a strong upregulation of colanic acid synthesis. The findings expand the scope of pathways affected by the csrA regulon and emphasize its importance as a global regulator.
Project description:Transcripitonal profiling of Escherichia coli K-12 W3110 comparing wild type and luxS mutants without or with 10%, 30% H2O2 treatments, two biological replicates for each condition