title: Transient conformational remodeling of folding proteins by GroES-individually and in concert with GroEL.
abstract: The commonly accepted dogma of the bacterial GroE chaperonin system entails protein folding mediated by cycles of several ATP-dependent sequential steps where GroEL interacts with the folding client protein. In contrast, we herein report GroES-mediated dynamic remodeling (expansion and compression) of two different protein substrates during folding: the endogenous substrate MreB and carbonic anhydrase (HCAII), a well-characterized protein folding model. GroES was also found to influence GroEL binding induced unfolding and compression of the client protein underlining the synergistic activity of both chaperonins, even in the absence of ATP. This previously unidentified activity by GroES should have important implications for understanding the chaperonin mechanism and cellular stress response. Our findings necessitate a revision of the GroEL/ES mechanism.
authors.affiliation: IFM-Department of Chemistry, Linköping University, 581 83 Linköping, Sweden ; Institut Fresnel, CNRS UMR 7249, Aix-Marseille Université, Ecole Centrale Marseille, Marseille, France.
authors.forename: Satish Babu
authors.initials: SB
authors.lastname: Moparthi
authors.affiliation: IFM-Department of Chemistry, Linköping University, 581 83 Linköping, Sweden.
authors.forename: Daniel
authors.initials: D
authors.lastname: Sjölander
authors.affiliation: IFM-Department of Chemistry, Linköping University, 581 83 Linköping, Sweden.
authors.forename: Laila
authors.initials: L
authors.lastname: Villebeck
authors.affiliation: IFM-Department of Chemistry, Linköping University, 581 83 Linköping, Sweden.
authors.forename: Bengt-Harald
authors.initials: BH
authors.lastname: Jonsson
authors.affiliation: IFM-Department of Chemistry, Linköping University, 581 83 Linköping, Sweden.
authors.forename: Per
authors.initials: P
authors.lastname: Hammarström
authors.affiliation: IFM-Department of Chemistry, Linköping University, 581 83 Linköping, Sweden.
authors.forename: Uno
authors.initials: U
authors.lastname: Carlsson
keywords: Carbonic anhydrase; Chaperone; FRET; Molten globule; MreB; Protein folding