Project description:We report that inhibition of rho by treatment with bicyclomycin, a potential inhibitor of rho affects H-NS binding to chromosome across most of the binding sites. For the current study, we have flag tagged H-NS by homologous recomination method. Cells were grown in the presence and absence of antibiotic bicylomyin. Chromatin immunoprecipitation was performed and anti flag antibody was used for immunoprecipitation. Immunoprecipitated samples both from BCM- and BCM + conditions were sequenced using HiSeq 1000 model. Input DNA was used as control for this experiment which was also sequenced. The 50-mer reads obtained were then mapped to Escherichia coli Mg1655 K-12 genome. Further analysis was carried out to calculate the ChIP signal score. We observed a drop in ChIP signal for bcm+ condition as compared to bcm-.
Project description:We report that inhibition of rho by treatment with bicyclomycin, a potential inhibitor of rho affects H-NS binding to chromosome across most of the binding sites. For the current study, we have flag tagged H-NS by homologous recomination method. Cells were grown in the presence and absence of antibiotic bicylomyin. Chromatin immunoprecipitation was performed and anti flag antibody was used for immunoprecipitation. Immunoprecipitated samples both from BCM- and BCM + conditions were sequenced using HiSeq 1000 model. Input DNA was used as control for this experiment which was also sequenced. The 50-mer reads obtained were then mapped to Escherichia coli Mg1655 K-12 genome. Further analysis was carried out to calculate the ChIP signal score. We observed a drop in ChIP signal for bcm+ condition as compared to bcm-. ChIP-seq data generated by Hiseq 1000 model of samples with bcm+ and bcm- in biological duplicates along with Input DNA as control
Project description:The transcription termination factor Rho is a global regulator of RNA polymerase (RNAP). Although individual Rho-dependent terminators have been studied extensively, less is known about the sites of RNAP regulation by Rho on a genome-wide scale. Using chromatin immunoprecipitation and microarrays (ChIP-chip), we examined changes in the distribution of Escherichia coli RNAP in response to the Rho-specific inhibitor bicyclomycin (BCM). We found ~200 Rho-terminated loci that were divided evenly into two classes: intergenic (at the ends of genes) and intragenic (within genes). The intergenic class contained noncoding RNAs such as small RNAs (sRNAs) and transfer RNAs (tRNAs), establishing a previously unappreciated role of Rho in termination of stable RNA synthesis. The intragenic class of terminators included a novel set of short antisense transcripts, as judged by a shift in the distribution of RNAP in BCM-treated cells that was opposite to the direction of the corresponding gene. These Rho-terminated antisense transcripts point to a novel role of noncoding transcription in E. coli gene regulation that may resemble the ubiquitous noncoding transcription recently found to play myriad roles in eukaryotic gene regulation. Chromatin immunoprecipitation (ChIP) experiments were performed using antibodies against RNA polymerase (Beta or Beta' subunit) in cells treated with 20ug/ml bicyclomycin or untreated cells. Differentially labeled ChIP DNA and genomic DNA were competitively hybridized to an E. coli K-12 MG1655 tiling array with overlapping probes at ~12bp spacing across the entire genome. The series contains 4 datasets.
Project description:The transcriptomes of Δrho mutant cells and of wild-type cells grown in RPMI medium with or without 40 or 80 µg/ml of BCM were analyzed using Agilent microarrays in order to analyze the effects of the Rho inhibitor bicyclomycin (BCM) treatment on antisense transcription and changes in the expression of protein coding genes. All antisense RNAs exhibiting higher levels in the rho mutant compared to the wild-type showed similar levels in BCM-treated wild-type cells (80 µg/ml BCM). In addition, microarray data revealed activation of the SaeR regulon in the presence of BCM as observed in the rho mutant.
Project description:The transcription termination factor Rho is a global regulator of RNA polymerase (RNAP). Although individual Rho-dependent terminators have been studied extensively, less is known about the sites of RNAP regulation by Rho on a genome-wide scale. Using chromatin immunoprecipitation and microarrays (ChIP-chip), we examined changes in the distribution of Escherichia coli RNAP in response to the Rho-specific inhibitor bicyclomycin (BCM). We found ~200 Rho-terminated loci that were divided evenly into two classes: intergenic (at the ends of genes) and intragenic (within genes). The intergenic class contained noncoding RNAs such as small RNAs (sRNAs) and transfer RNAs (tRNAs), establishing a previously unappreciated role of Rho in termination of stable RNA synthesis. The intragenic class of terminators included a novel set of short antisense transcripts, as judged by a shift in the distribution of RNAP in BCM-treated cells that was opposite to the direction of the corresponding gene. These Rho-terminated antisense transcripts point to a novel role of noncoding transcription in E. coli gene regulation that may resemble the ubiquitous noncoding transcription recently found to play myriad roles in eukaryotic gene regulation.