The chaperonin ATPase cycle: mechanism of allosteric switching and movements of substrate-binding domains in GroEL

Cell. 1996 Oct 18;87(2):241-51. doi: 10.1016/s0092-8674(00)81342-2.


Chaperonin-assisted protein folding proceeds through cycles of ATP binding and hydrolysis by the large chaperonin GroEL, which undergoes major allosteric rearrangements. Interaction between the two back-to-back seven-membered rings of GroEL plays an important role in regulating binding and release of folding substrates and of the small chaperonin GroES. Using cryo-electron microscopy, we have obtained three-dimensional reconstructions to 30 A resolution for GroEL and GroEL-GroES complexes in the presence of ADP, ATP, and the nonhydrolyzable ATP analog, AMP-PNP. Nucleotide binding to the equatorial domains of GroEL causes large rotations of the apical domains, containing the GroES and substrate protein-binding sites. We propose a mechanism for allosteric switching and describe conformational changes that may be involved in critical steps of folding for substrates encapsulated by GroES.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases / metabolism
  • Adenosine Triphosphate / metabolism
  • Allosteric Regulation
  • Bacterial Proteins / physiology
  • Binding Sites
  • Chaperonin 10 / physiology
  • Chaperonin 60 / physiology*
  • Escherichia coli
  • Macromolecular Substances
  • Microscopy, Electron
  • Models, Molecular
  • Movement
  • Protein Structure, Tertiary


  • Bacterial Proteins
  • Chaperonin 10
  • Chaperonin 60
  • Macromolecular Substances
  • Adenosine Triphosphate
  • Adenosine Triphosphatases