Adaptation in bacterial flagellar and motility systems: from regulon members to 'foraging'-like behavior in E. coli

Nucleic Acids Res. 2007;35(13):4441-52. doi: 10.1093/nar/gkm456. Epub 2007 Jun 18.


Bacterial flagellar motility and chemotaxis help cells to reach the most favorable environments and to successfully compete with other micro-organisms in response to external stimuli. Escherichia coli is a motile gram-negative bacterium, and the flagellar regulon in E. coli is controlled by a master regulator FlhDC as well as a second regulator, flagellum-specific sigma factor, sigma(F). To define the physiological role of these two regulators, we carried out transcription profiling experiments to identify, on a genome-wide basis, genes under the control of these two regulators. In addition, the synchronized pattern of increasing CRP activity causing increasing FlhDC expression with decreasing carbon source quality, together with the apparent coupling of motility activity with the activation of motility and chemotaxis genes in poor quality carbon sources, highlights the importance of CRP activation in allowing E. coli to devote progressively more of its limited reserves to search out better conditions. In adaptation to a variety of carbon sources, the motile bacteria carry out tactical responses by increasing flagellar operation but restricting costly flagellar synthesis, indicating its capability of strategically using the precious energy in nutrient-poor environments for maximizing survival.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adaptation, Physiological / genetics*
  • Binding Sites
  • Carbon / metabolism
  • Chemotaxis / genetics
  • Cyclic AMP Receptor Protein / metabolism
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • DNA-Binding Proteins / physiology
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism
  • Escherichia coli / physiology
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / metabolism
  • Escherichia coli Proteins / physiology*
  • Flagella / genetics*
  • Gene Expression Profiling
  • Gene Expression Regulation, Bacterial
  • Movement
  • Regulon*
  • Sigma Factor / genetics
  • Sigma Factor / metabolism
  • Sigma Factor / physiology
  • Trans-Activators / genetics
  • Trans-Activators / metabolism
  • Trans-Activators / physiology
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Transcription Factors / physiology*


  • Cyclic AMP Receptor Protein
  • DNA-Binding Proteins
  • Escherichia coli Proteins
  • Sigma Factor
  • Trans-Activators
  • Transcription Factors
  • crp protein, E coli
  • flhC protein, E coli
  • flhD protein, E coli
  • sporulation-specific sigma factors
  • Carbon