Intramolecular Motions of Chaperonin Play Important Role in Protein Repair

Amazing biomolecular mechanism similar to domino effect


A research group led by Prof. Yuji Sasaki (Graduate School of Frontier Sciences, the University of Tokyo), Hiroshi Sekiguchi (Japan Synchrotron Radiation Research Institute), and Prof. Masafumi Yohda (The Tokyo University of Agriculture and Technology) has for the first time succeeded in the real-time and high-precision monitoring of intramolecular motions of the chaperonin molecule at the single-molecule level. Chaperonin plays an important role in the repair of nonnative proteins and has a cylinder structure in which two oligomeric rings are stacked. It was discovered that the lid of the chaperonin ring partially closed after ATP binding to chaperonin, and the closed ring structure subsequently twisted counterclockwise as viewed from above. A “domino-effect” series of intramolecular motions were monitored at a temporal resolution of 30 ms and picometer-level position accuracy by a diffracted X-ray tracking technique developed by Professor Sasaki in 1998. High-speed and high-precision monitoring of intramolecular motion observed in this study may open up new strategies for drug development and increase understanding of intermolecular interaction in the future.