A single ring is sufficient for productive chaperonin-mediated folding in vivo

Mol Cell. 1998 Jul;2(1):93-9. doi: 10.1016/s1097-2765(00)80117-3.


Facilitated protein folding by the double toroidal bacterial chaperonin, GroEL/GroES, proceeds by a "two-stroke engine" mechanism in which an allosteric interaction between the two rings synchronizes the reaction cycle by controlling the binding and release of cochaperonin. Using chimeric chaperonin molecules assembled by fusing equatorial and apical domains derived from GroEL and its mammalian mitochondrial homolog, Hsp60, we show that productive folding by Hsp60 and its cognate cochaperonin, Hsp10, proceeds in vitro and in vivo without the formation of a two-ring structure. This simpler "one-stroke" engine works because Hsp60 has a different mechanism for the release of its cochaperonin cap and bound target protein.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenosine Triphosphatases / chemistry
  • Adenosine Triphosphatases / genetics
  • Adenosine Triphosphatases / physiology
  • Allosteric Regulation
  • Chaperonin 10 / chemistry*
  • Chaperonin 10 / genetics
  • Chaperonin 10 / physiology
  • Chaperonin 60 / chemistry*
  • Chaperonin 60 / genetics
  • Chaperonin 60 / physiology
  • Humans
  • Mutagenesis, Site-Directed
  • Protein Binding
  • Protein Folding*
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / physiology
  • Structure-Activity Relationship


  • Chaperonin 10
  • Chaperonin 60
  • Recombinant Fusion Proteins
  • Adenosine Triphosphatases