Project description:Plasmids are widely used across molecular biology and are becoming increasingly valuable products, but robust plasmid replication is held back by stability issues in the host. This study investigated how Escherichia coli responds to plasmid stress at the transcriptional level by modulating plasmid copy number, plasmid size, selection marker and carbon source. This GEO contains controls from this study alone.
Project description:To demonstrate plasmid transferability by conjugation, cultures of the donor S. Infantis, and recipient Escherichia coli (E. coli) K12 were mated. S. Infantis and transconjugant were screened for resistance genes.
Project description:Transcription profiles in BL21, BL21/pOri1 and BL21/pOri2 were analysed using DNA microarray technology. BL21, BL21/pOri1 or BL21/pOri2 strains were cultured at chemostat status and harvested after the cultivation arrived steady status. Keywords: Effects of plasmid DNA on Escherichia coli metabolism
Project description:PdeL is a transcription regulator and c-di-GMP specific phosphodiesterase in Escherichia coli. To address the transcription regulator function of PdeL we analyzed the transcriptomes of four E. coli K12 strains during the exponential growth phase by RNA-sequencing. These four strains included (1) wild-type E. coli K12 strain BW30270 carrying an empty vector control plasmid, (2) an isogenic pdeL deletion mutant carrying the control plasmid, as well as the pdeL mutant that was complemented with (3) a plasmid carrying pdeL under control of the IPTG-inducible tac promoter or (4) a plasmid encoding a fusion protein of the PdeL’s DNA-binding domain and the C-terminal dimerization domain of phage Lambda cI repressor (PdeL-DBD_cI-C). Expression of plasmid-encoded pdeL and pdeL-DBD_cI-C, respectively, was induced by addition of IPTG for 15 minutes prior to RNA isolation. Analyses of the RNA-seq data revealed that plasmid-provided PdeL (and PdeL-DBD_cI-C) repress transcription of class II flagellar genes and presumably regulate the transcription of additional loci, while only little differences were observed between the transcriptomes of wild-type strain BW30270 and its isogenic pdeL mutant.
