NCBI Logo
GEO Logo
   NCBI > GEO > Accession DisplayHelp Not logged in | LoginHelp
GEO help: Mouse over screen elements for information.
          Go
Sample GSM1484357 Query DataSets for GSM1484357
Status Public on Aug 12, 2020
Title SigH (30 ℃)
Sample type SRA
 
Source name SigH (30 ℃)
Organism Escherichia coli str. K-12 substr. MG1655
Characteristics chip antibody: Anti-myc (9E10) (Santa Cruz, Dallas, TX)
substrain: MG1655
Treatment protocol Then, cells were diluted to 1:100 into fresh same minimal medium and cultured at 30 ℃ up to mid-exponential phase (OD600 = 0.6). To treat the heat shock, cultured cells were subsequently mixed slowly with pre-warmed 55 ℃ media of equivalent volume to adjust to 42 ℃. For non-heat shocked condition, all experiments were performed in same manner except using 30 ℃ instead of 55 ℃ media. All mixture were further incubated shaking at 30 ℃ and 42 ℃ for 5 min.
Growth protocol Only in ChIP-assay for σ32, E. coli K12 MG1655 rpoH::8Myc::Kan (MG1655_rpoHmyc) isogenic strain was used, which was constructed as replacing rpoH to 8myc-rpoH encoding eight copies of the c-myc epitope tag and kan at the 3’ end. And two types of cells (50 ml) were inoculated into M9 minimal media of 5 ml supplemented 0.2% glucose, and grown at 30 ℃ with constant agitation overnight.
Extracted molecule genomic DNA
Extraction protocol Cultured cells of 50 ml were cross-linked by 1% formaldehyde at room temperature for 30 min. To quench the unused formaldehyde and to stop the reaction, 2 mL of 2.5 M glycine was added to the cell. The cells were washed three times with 50 mL of ice-cold Tris-buffered saline (TBS) and then were incubated with 0.5 mL of lysis buffer (50 mM Tris-HCl (pH 7.5), 100 mM NaCl, 1 mM EDTA, 1 μg/mL RNaseA, protease inhibitor cocktail and 1 kU Ready-Lyse lysozyme (Epicentre, Madison, WI)) at 37 ℃ for 30 min1. The cells were then treated with 0.5 mL of 2×IP buffer (100 mM Tris-HCl (pH 7.5), 100 mM NaCl, 1 mM EDTA, 2%(v/v) Triton X-100, and protease inhibitor cocktail), followed by incubation on ice for 30 min. For the lysis of cell and fragmentation of DNA, the lysate was then sonicated in an ice bath using Sonic Dismembrator Model 500 (four times for 20 s each, output level, 2.5). The size distribution of fragmented DNAs was confirmed using agarose gel electrophoresis (200-400 bp) after removing cell debris by centrifugation.
After stringent sequential washings, the IP-DNAs were reverse-crosslinked from DNA-protein complexes at 65 ℃ overnight. The RNAs and proteins in the supernatant were degraded with 1 µg RNase A and 8 µg protease K, respectively. The IP-DNAs were further purified using Qiagen PCR purification kit. The purified IP-DNAs were then modified and amplified by TruSeq DNA Sample Prep Kit v2 for the Illumina next-generation sequencing according to the manufacturer’s instruction (Illumina). The PCR-amplified DNA products were then loaded onto 2% agarose gel and extracted using QIAquick gel purification columns.
 
Library strategy ChIP-Seq
Library source genomic
Library selection ChIP
Instrument model Illumina MiSeq
 
Description SigH30seq_jMRSP_Subtr.gff
Data processing Basecalls performed using CASAVA version 1.4
All sequencing reads were mapped to E. coli MG1655 reference genome (NC_000913) using CLC Genomics Workbench5 with the length fraction of 0.9 and the similarity of 0.99.
To capture target protein binding sites corresponding genomic position of mapped reads start position (MRSP) was counted and stored for visual inspection using in-house scripts.
Genome_build: NC_000913.3
Supplementary_files_format_and_content: gff file is generated by in-house script
 
Submission date Aug 22, 2014
Last update date Aug 12, 2020
Contact name Byung-Kwan Cho
Organization name KAIST
Lab Systems and Synthetic Biology Lab
Street address 291 Daehak-ro
City Daejeon
ZIP/Postal code 305-701
Country South Korea
 
Platform ID GPL17439
Series (2)
GSE60668 In vivo probing of promoter overlapping between σ-factors in Escherichia coli (ChIP-Seq)
GSE60669 In vivo probing of promoter overlapping between ?-factors in Escherichia coli
Relations
BioSample SAMN03002767
SRA SRX685354

Supplementary data files not provided
SRA Run SelectorHelp
Raw data are available in SRA
Processed data are available on Series record

| NLM | NIH | GEO Help | Disclaimer | Accessibility |
NCBI Home NCBI Search NCBI SiteMap