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  • The EMBO Journal (2006) 25, 4567 - 4576
  • doi:10.1038/sj.emboj.7601326

Published online: 14 September 2006

Fast-scanning atomic force microscopy reveals the ATP/ADP-dependent conformational changes of GroEL

Masatoshi Yokokawa1, Chieko Wada1, Toshio Ando2, Nobuaki Sakai3, Akira Yagi3, Shige H Yoshimura1 and Kunio Takeyasu1

  1. Laboratory of Plasma Membrane and Nuclear Signaling, Kyoto University Graduate School of Biostudies, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto, Japan
  2. Department of Physics, Faculty of Science, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa, Japan
  3. OLYMPUS Corporation, Hachioji, Tokyo, Japan

Correspondence to:

Masatoshi Yokokawa, Laboratory of Plasma Membrane and Nuclear Signaling, Kyoto University Graduate School of Biostudies, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto, Japan. Tel./Fax: +81 75 753 6852; E-mail: yokokawa@lif.kyoto-u.ac.jp

Received 21 February 2006; Accepted 14 August 2006

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 (approx1.0 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.

  • Keywords:

    • atomic force microscopy,
    • chaperonin,
    • two-dimensional protein crystal