Transient association of newly synthesized unfolded proteins with the heat-shock GroEL protein

Nature. 1988 Nov 17;336(6196):254-7. doi: 10.1038/336254a0.


It has been suggested that newly synthesized proteins are maintained in their unfolded state by cellular ATP-driven factors which may prevent or reverse the formation of misfolded structures or promote the correct assembly of oligomeric proteins or post-translational secretion. Using a photocross-linking approach, we have identified the 20S heat-shock GroEL protein as the major cytosolic component which forms a complex with the unfolded newly synthesized pre-beta-lactamase or chloramphenicol acetyltransferase in Escherichia coli. Dissociation of these complexes is ATP-dependent. The unfolded state of pre-beta-lactamase, maintained by the transient interaction with GroEL, may be essential for the secretion of this protein.

MeSH terms

  • Adenosine Triphosphate / pharmacology
  • Affinity Labels
  • Bacterial Proteins / metabolism*
  • Chaperonin 60
  • Chloramphenicol O-Acetyltransferase / metabolism*
  • Cross-Linking Reagents
  • Disulfides / metabolism
  • Dithiothreitol / pharmacology
  • Enzyme Precursors / metabolism*
  • Escherichia coli / metabolism
  • Heat-Shock Proteins / metabolism*
  • Photochemistry
  • Plasmids
  • Protein Biosynthesis
  • Protein Conformation
  • Protein Processing, Post-Translational
  • beta-Lactamases / metabolism*


  • Affinity Labels
  • Bacterial Proteins
  • Chaperonin 60
  • Cross-Linking Reagents
  • Disulfides
  • Enzyme Precursors
  • Heat-Shock Proteins
  • Adenosine Triphosphate
  • Chloramphenicol O-Acetyltransferase
  • beta-Lactamases
  • Dithiothreitol