Successive action of DnaK, DnaJ and GroEL along the pathway of chaperone-mediated protein folding

Abstract
The main stress proteins of Escherichia coli function in an ordered protein-folding reaction. DnaK (heat-shock protein 70) recognizes the folding poly-peptide as an extended chain and cooperates with DnaJ in stabilizing an intermediate conformational state lacking ordered tertiary structure. Dependent on GrpE and ATP hydrolysis, the protein is then transferred to GroEL (heat-shock protein 60) which acts catalytically in the production of the native state. This sequential mechanism of chaperone action may represent an important pathway for the folding of newly synthesized polypeptides.