AraC protein, regulation of the l-arabinose operon in Escherichia coli, and the light switch mechanism of AraC action

FEMS Microbiol Rev. 2010 Sep;34(5):779-96. doi: 10.1111/j.1574-6976.2010.00226.x. Epub 2010 Apr 8.


This review covers the physiological aspects of regulation of the arabinose operon in Escherichia coli and the physical and regulatory properties of the operon's controlling gene, araC. It also describes the light switch mechanism as an explanation for many of the protein's properties. Although many thousands of homologs of AraC exist and regulate many diverse operons in response to many different inducers or physiological states, homologs that regulate arabinose-catabolizing genes in response to arabinose were identified. The sequence similarities among them are discussed in light of the known structure of the dimerization and DNA-binding domains of AraC.

Publication types

  • Review

MeSH terms

  • Allosteric Site
  • Amino Acid Sequence
  • AraC Transcription Factor / metabolism*
  • Arabinose / genetics*
  • DNA, Bacterial / genetics
  • DNA, Bacterial / metabolism
  • Escherichia coli / genetics*
  • Escherichia coli / radiation effects*
  • Escherichia coli Proteins / metabolism*
  • Fluorescence
  • Gene Expression Regulation, Bacterial / radiation effects*
  • Models, Molecular
  • Molecular Sequence Data
  • Operon / genetics*
  • Protein Binding
  • Protein Multimerization
  • Protein Structure, Tertiary / physiology
  • Sequence Alignment
  • Trans-Activators / genetics


  • AraC Transcription Factor
  • AraC protein, E coli
  • DNA, Bacterial
  • Escherichia coli Proteins
  • Trans-Activators
  • Arabinose