title: Asymmetrical interaction of GroEL and GroES in the ATPase cycle of assisted protein folding.
abstract: The chaperonins GroEL and GroES of Escherichia coli facilitate protein folding in an adenosine triphosphate (ATP)-dependent reaction cycle. The kinetic parameters for the formation and dissociation of GroEL-GroES complexes were analyzed by surface plasmon resonance. Association of GroES and subsequent ATP hydrolysis in the interacting GroEL toroid resulted in the formation of a stable GroEL:ADP:GroES complex. The complex dissociated as a result of ATP hydrolysis in the opposite GroEL toroid, without formation of a symmetrical GroEL:(GroES)2 intermediate. Dissociation was accelerated by the addition of unfolded polypeptide. Thus, the functional chaperonin unit is an asymmetrical GroEL:GroES complex, and substrate protein plays an active role in modulating the chaperonin reaction cycle.
authors.affiliation: Howard Hughes Medical Institute, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.
authors.forename: M K
authors.initials: MK
authors.lastname: Hayer-Hartl
authors.forename: J
authors.initials: J
authors.lastname: Martin
authors.forename: F U
authors.initials: FU
authors.lastname: Hartl
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism; D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism; D018835:Chaperonin 10 / Q000737:chemistry / Q000378:metabolism*; D018834:Chaperonin 60 / Q000737:chemistry / Q000378:metabolism*; D019286:Endopeptidase K; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D017510:Protein Folding; D012697:Serine Endopeptidases / Q000378:metabolism
chemical_list: D018835:Chaperonin 10; D018834:Chaperonin 60; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D012697:Serine Endopeptidases; D019286:Endopeptidase K; D000251:Adenosine Triphosphatases; D008274:Magnesium