TITLE:
Cytosolic chaperonin CCT possesses GTPase activity
AUTHORS:
Susumu Noguchi, Kazuyoshi Toyoshima, Soh Yamamoto, Toshio Miyazaki, Michiro Otaka, Sumio Watanabe, Katsunori Imai, Haruki Senoo, Ryoji Kobayashi, Mitsutoshi Jikei, Yasushi Kawata, Hiroshi Kubota, Hideaki Itoh
KEYWORDS:
Chaperonin; Molecular Chaperone; Protein Folding, Gtp
JOURNAL NAME:
American Journal of Molecular Biology,
Vol.1 No.3,
October
11,
2011
ABSTRACT: Cytosolic chaperonin CCT (also known as TRiC) is a hetero-oligomeric cage-like molecular chaperone that assists in protein folding by ATPase cycle-dependent conformational changes. However, role of the nucleo-tide binding and hydrolysis in CCT-assisted protein folding is still poorly understood. We purified CCT by using ATP-Sepharose and other columns, and found that CCT possesses ability to hydrolyze GTP, with an activity level very similar to the ATPase activity. CCT was more resistant to proteinase K treatment in the presence of GTP or ATP. These results suggest that the GTPase activity of CCT may play a role in chaperone-assisted protein folding.