GroEL-Assisted Protein Folding: Does It Occur Within the Chaperonin Inner Cavity?

The folding of protein molecules in the GroEL inner cavity under the co-chaperonin GroES lid is widely accepted as a crucial event of GroEL-assisted protein folding. This review is focused on the data showing that GroEL-assisted protein folding may proceed out of the complex with the chaperonin. The models of GroEL-assisted protein folding assuming ligand-controlled dissociation of nonnative proteins from the GroEL surface and their folding in the bulk solution are also discussed.