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Sample GSM2770996 Query DataSets for GSM2770996
Status Public on Apr 21, 2018
Title Ribosome profiling 5 min after shift to 10°C in WT cells
Sample type SRA
 
Source name MG1655
Organism Escherichia coli
Characteristics strain background: MG1655
genotype/variation: wild type
temperature: 10°C
molecule subtype: Ribosome protected mRNA
Treatment protocol For in vivo DMS modification, 15 mL of E. coli culture was incubated with 750 µL DMS. Incubation was performed for 2 min at 37°C or for 45 min at 10°C. DMS was quenched by adding 30 mL 0°C stop solution (30% β-mercaptoethanol, 25% isoamyl alcohol), after which cells were quickly put on ice, collected by centrifugation at 8000 x g, 4 °C for 2 min, and washed with 8 mL 30% BME solution. Cells were then resuspended in 450 µL total RNA lysis buffer (10 mM EDTA, 50 mM sodium acetate pH 5.5), and total RNA was purified with hot acid phenol (Ambion).
Growth protocol All culture experiments were performed in MOPS medium supplemented with 0.2% glucose, 19 amino acids (without methionine), vitamins, bases and micronutrients (MOPS rich defined medium minus methionine, Teknova). Cells were grown in an overnight liquid culture at 37°C, diluted to an OD420 = .001 in fresh medium and grown until OD420 reached 0.4 where samples were collected. For 10°C samples, cultures were grown to OD420 = 1.1 at 37°C and cold shock was performed by mixing 70mL of 37°C culture with 130mL of 0°C media pre-chilled in ice-water slurry, with continued growth of the culture in a 10°C shaker.
Extracted molecule total RNA
Extraction protocol Extraction was performed as described in detail previously (Li et al., 2012; Oh et al., 2011; Rouskin et al., 2014). For ribosome profiling, 200 ml of cell culture was rapidly filtered by passing through a nitrocellulose filter. Cell pellets was were rapidly collected using a pre-warmed metal table crumber, flash frozen in liquid nitrogen, and combined with frozen droplets of lysis buffer. Cells and lysis buffer were pulverized in 10 ml canisters (Retsch) pre-chilled in liquid nitrogen using Qiagen TissueLyser II. Pulverized lysate was thawed on ice and clarified by centrifugation at 4°C. Lysate containing 0.5 mg of RNA was digested for 1 h with 750 U of micrococcal nuclease (Roche) at 25°C. The ribosome-protected RNA fragments were isolated using a sucrose gradient followed by hot acid phenol extraction.
mRNA fragments were size selected via gel purification, and ligated to 5' adenylated DNA oligo. After reverse transcription, the single stranded DNA was circularized, and PCR amplified (Oh et al., 2011; Li et al., 2014; Rouskin et al., 2014).
 
Library strategy RNA-Seq
Library source transcriptomic
Library selection cDNA
Instrument model Illumina HiSeq 2000
 
Description Rib_wt_5min_center
Data processing Basecalls performed using Casava versions 1.6 or 1.7.
Sequenced reads were trimmed for adaptor sequence.
Trimmed reads were sequentially aligned using Bowtie v0.12.7 to E. coli rRNA and noncoding RNA allowing one mismatch. Reads aligning to any of these indices were discarded.
The remaining reads were aligned using Bowtie v0.12.7 against E. coli MG1655 genome using parameters -v1 -m2 -k1.
Bowtie alignments against the E. coli genome were converted to wiggle files. For ribosome footprints and mRNA-seq, the position of each alignment is distributed into several nucleotides in the center of each read. For each read, the center residues that are at least 10 nucleotides away from either ends were given the same score, which is weighted by the length of the fragment [Oh et al,. Cell 147, 1295 (2011)]. Scores therefore represent the number of read alignments attributed to each genomic position under each scoring scheme. For DMS-seq, the position of each alignment was the position immediately 5' of the 5' end of the read.
Genome_build: NC000913.2
Supplementary_files_format_and_content: Wiggle files with two columns: first column containing chromosome positions and second column containing the number of reads mapped to the position (see publication for details).
 
Submission date Sep 04, 2017
Last update date May 15, 2019
Contact name Yan Zhang
E-mail(s) yan.jenny.zhang@gmail.com
Organization name UC San Francisco
Department Microbiology and Immunology
Lab Carol Gross
Street address 600 16th Street
City San Francisco
State/province CA
ZIP/Postal code 94158
Country USA
 
Platform ID GPL14548
Series (1)
GSE103421 A stress response that monitors and regulates mRNA structure is central to cold-shock adaptation
Relations
BioSample SAMN07602617
SRA SRX3157114

Supplementary file Size Download File type/resource
GSM2770996_Rib_wt_5min_center_for.wig.gz 3.2 Mb (ftp)(http) WIG
GSM2770996_Rib_wt_5min_center_rev.wig.gz 3.5 Mb (ftp)(http) WIG
SRA Run SelectorHelp
Processed data provided as supplementary file
Raw data are available in SRA

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