title: Fast-scanning atomic force microscopy reveals the ATP/ADP-dependent conformational changes of GroEL.
abstract: In order to fold non-native proteins, chaperonin GroEL undergoes numerous conformational changes and GroES binding in the ATP-dependent reaction cycle. We constructed the real-time three-dimensional-observation system at high resolution using a newly developed fast-scanning atomic force microscope. Using this system, we visualized the GroES binding to and dissociation from individual GroEL with a lifetime of 6 s (k=0.17 s(-1)). We also caught ATP/ADP-induced open-closed conformational changes of individual GroEL in the absence of qGroES and substrate proteins. Namely, the ATP/ADP-bound GroEL can change its conformation 'from closed to open' without additional ATP hydrolysis. Furthermore, the lifetime of open conformation in the presence of ADP ( approximately 1.0 s) was apparently lower than those of ATP and ATP-analogs (2-3 s), meaning that ADP-bound open-form is structurally less stable than ATP-bound open-form. These results indicate that GroEL has at least two distinct open-conformations in the presence of nucleotide; ATP-bound prehydrolysis open-form and ADP-bound open-form, and the ATP hydrolysis in open-form destabilizes its open-conformation and induces the 'from open to closed' conformational change of GroEL.
authors.affiliation: Laboratory of Plasma Membrane and Nuclear Signaling, Kyoto University Graduate School of Biostudies, Kyoto, Japan. yokokawa@lif.kyoto-u.ac.jp
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Yokokawa
authors.forename: Chieko
authors.initials: C
authors.lastname: Wada
authors.forename: Toshio
authors.initials: T
authors.lastname: Ando
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Sakai
authors.forename: Akira
authors.initials: A
authors.lastname: Yagi
authors.forename: Shige H
authors.initials: SH
authors.lastname: Yoshimura
authors.forename: Kunio
authors.initials: K
authors.lastname: Takeyasu
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism*; D018835:Chaperonin 10 / Q000648:ultrastructure; D018834:Chaperonin 60 / Q000737:chemistry* / Q000648:ultrastructure*; D004926:Escherichia coli / Q000737:chemistry*; D007700:Kinetics; D018625:Microscopy, Atomic Force / Q000379:methods*; D008954:Models, Biological; D008958:Models, Molecular; D011485:Protein Binding; D011487:Protein Conformation; D012996:Solutions
chemical_list: D018835:Chaperonin 10; D018834:Chaperonin 60; D012996:Solutions; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate