Termination factor Rho and its cofactors NusA and NusG silence foreign DNA in E. coli

Science. 2008 May 16;320(5878):935-8. doi: 10.1126/science.1152763.


Transcription of the bacterial genome by the RNA polymerase must terminate at specific points. Transcription can be terminated by Rho factor, an essential protein in enterobacteria. We used the antibiotic bicyclomycin, which inhibits Rho, to assess its role on a genome-wide scale. Rho is revealed as a global regulator of gene expression that matches Escherichia coli transcription to translational needs. We also found that genes in E. coli that are most repressed by Rho are prophages and other horizontally acquired portions of the genome. Elimination of these foreign DNA elements increases resistance to bicyclomycin. Although rho remains essential, such reduced-genome bacteria no longer require Rho cofactors NusA and NusG. Deletion of the cryptic rac prophage in wild-type E. coli increases bicyclomycin resistance and permits deletion of nusG. Thus, Rho termination, supported by NusA and NusG, is required to suppress the toxic activity of foreign genes.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Bacteriophage lambda / genetics
  • Bridged Bicyclo Compounds, Heterocyclic / pharmacology
  • Coliphages / genetics
  • DNA, Intergenic
  • Escherichia coli / drug effects
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism
  • Escherichia coli O157 / genetics*
  • Escherichia coli O157 / metabolism
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / metabolism*
  • Gene Expression Regulation, Bacterial
  • Gene Silencing*
  • Genome, Bacterial
  • Oligonucleotide Array Sequence Analysis
  • Peptide Elongation Factors / metabolism*
  • Prophages / genetics*
  • Proteome
  • Rho Factor / antagonists & inhibitors
  • Rho Factor / metabolism*
  • Transcription Factors / metabolism*
  • Transcription, Genetic
  • Transcriptional Elongation Factors


  • Anti-Bacterial Agents
  • Bridged Bicyclo Compounds, Heterocyclic
  • DNA, Intergenic
  • Escherichia coli Proteins
  • NusG protein, E coli
  • Peptide Elongation Factors
  • Proteome
  • Rho Factor
  • Transcription Factors
  • Transcriptional Elongation Factors
  • nusA protein, E coli
  • bicozamycin

Associated data

  • GEO/GSE10345