E. coli Fis protein insulates the cbpA gene from uncontrolled transcription

PLoS Genet. 2013;9(1):e1003152. doi: 10.1371/journal.pgen.1003152. Epub 2013 Jan 17.


The Escherichia coli curved DNA binding protein A (CbpA) is a poorly characterised nucleoid associated factor and co-chaperone. It is expressed at high levels as cells enter stationary phase. Using genetics, biochemistry, and genomics, we have examined regulation of, and DNA binding by, CbpA. We show that Fis, the dominant growth-phase nucleoid protein, prevents CbpA expression in growing cells. Regulation by Fis involves an unusual "insulation" mechanism. Thus, Fis protects cbpA from the effects of a distal promoter, located in an adjacent gene. In stationary phase, when Fis levels are low, CbpA binds the E. coli chromosome with a preference for the intrinsically curved Ter macrodomain. Disruption of the cbpA gene prompts dramatic changes in DNA topology. Thus, our work identifies a novel role for Fis and incorporates CbpA into the growing network of factors that mediate bacterial chromosome structure.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carrier Proteins* / genetics
  • Carrier Proteins* / metabolism
  • Chromosomes, Bacterial* / metabolism
  • Chromosomes, Bacterial* / ultrastructure
  • DNA, Bacterial / chemistry
  • DNA, Bacterial / genetics
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Escherichia coli Proteins* / genetics
  • Escherichia coli Proteins* / metabolism
  • Escherichia coli* / chemistry
  • Escherichia coli* / genetics
  • Factor For Inversion Stimulation Protein* / genetics
  • Factor For Inversion Stimulation Protein* / metabolism
  • Gene Expression Regulation, Bacterial
  • Molecular Chaperones / genetics
  • Molecular Chaperones / metabolism
  • Promoter Regions, Genetic
  • Transcription, Genetic


  • Carrier Proteins
  • CbpM protein, E coli
  • DNA, Bacterial
  • DNA-Binding Proteins
  • Escherichia coli Proteins
  • Factor For Inversion Stimulation Protein
  • Fis protein, E coli
  • Molecular Chaperones