Molecular Mechanism of Chaperonin GroEL: The Role of ATP and the Substrate Protein

The chaperonin GroEL is an essential molecular chaperone that assists protein folding in the cell. ATP-dependent conformational change of GroEL leads to the stable binding of cochaperonin GroES, forming a cage-shaped complex that accommodates a substrate protein to complete the folding. After the elucidation of the outline of the molecular mechanism over the last decade, now we are ready to answer the important questions; how GroEL encapsulate the substrate protein? How the substrate protein influences the functional cycle of GroEL? What is the role of ATP hydrolysis in the GroEL-assisted folding? Is the folding in the GroEL-ES cavity is same as that in the bulk solution? Here I review the recent progress on the GroEL study and discuss the essential role of chaperonin GroEL.