Dynamics of the chaperonin ATPase cycle: implications for facilitated protein folding

Science. 1994 Jul 29;265(5172):659-66. doi: 10.1126/science.7913555.


The Escherichia coli chaperonins GroEL and GroES facilitate protein folding in an adenosine triphosphate (ATP)-dependent manner. After a single cycle of ATP hydrolysis by the adenosine triphosphatase (ATPase) activity of GroEL, the bi-toroidal GroEL formed a stable asymmetric ternary complex with GroES and nucleotide (bulletlike structures). With each subsequent turnover, ATP was hydrolyzed by one ring of GroEL in a quantized manner, completely releasing the adenosine diphosphate and GroES that were tightly bound to the other ring as a result of the previous turnover. The catalytic cycle involved formation of a symmetric complex (football-like structures) as an intermediate that accumulated before the rate-determining hydrolytic step. After one to two cycles, most of the substrate protein dissociated still in a nonnative state, which is consistent with intermolecular transfer of the substrate protein between toroids of high and low affinity. A unifying model for chaperonin-facilitated protein folding based on successive rounds of binding and release, and partitioning between committed and kinetically trapped intermediates, is proposed.

Publication types

  • Review

MeSH terms

  • Adenosine Triphosphatases / metabolism*
  • Bacterial Proteins / metabolism*
  • Binding Sites
  • Chaperonin 10
  • Chaperonin 60
  • Heat-Shock Proteins / metabolism*
  • Kinetics
  • Models, Chemical
  • Protein Folding*
  • Ribulose-Bisphosphate Carboxylase / metabolism


  • Bacterial Proteins
  • Chaperonin 10
  • Chaperonin 60
  • Heat-Shock Proteins
  • Adenosine Triphosphatases
  • Ribulose-Bisphosphate Carboxylase