TY - JOUR
T1 - Effect of the C-terminal truncation on the functional cycle of chaperonin GroEL
T2 - Implication that the C-terminal region facilitates the transition from the folding-arrested to the folding-competent state
AU - Suzuki, Mihoko
AU - Ueno, Taro
AU - Iizuka, Ryo
AU - Miura, Takahiro
AU - Zako, Tamotsu
AU - Akahori, Rena
AU - Miyake, Takeo
AU - Shimamoto, Naonobu
AU - Aoki, Mutsuko
AU - Tanii, Takashi
AU - Ohdomari, Iwao
AU - Funatsu, Takashi
PY - 2008/8/29
Y1 - 2008/8/29
N2 - To elucidate the exact role of the C-terminal region of GroEL in its functional cycle, the C-terminal 20-amino acid truncated mutant of GroEL was constructed. The steady-state ATPase rate and duration of GroES binding showed that the functional cycle of the truncated GroEL is extended by ∼2 s in comparison with that of the wild type, without interfering with the basic functions of GroEL. We have proposed a model for the functional cycle of GroEL, which consists of two rate-limiting steps of ∼3- and ∼5-s duration (Ueno, T., Taguchi, H., Tadakuma, H., Yoshida, M., and Funatsu, T. (2004) Mol. Cell 14, 423-434). According to the model, detailed kinetic studies were performed. We found that a 20-residue truncation of the C terminus extends the time until inorganic phosphate is generated and the time for arresting protein folding in the central cavity, i.e. the lifetime of the first rate-limiting step in the functional cycle, to an ∼5-s duration. These results suggest that the integrity of the C-terminal region facilitates the transition from the first to the second rate-limiting state.
AB - To elucidate the exact role of the C-terminal region of GroEL in its functional cycle, the C-terminal 20-amino acid truncated mutant of GroEL was constructed. The steady-state ATPase rate and duration of GroES binding showed that the functional cycle of the truncated GroEL is extended by ∼2 s in comparison with that of the wild type, without interfering with the basic functions of GroEL. We have proposed a model for the functional cycle of GroEL, which consists of two rate-limiting steps of ∼3- and ∼5-s duration (Ueno, T., Taguchi, H., Tadakuma, H., Yoshida, M., and Funatsu, T. (2004) Mol. Cell 14, 423-434). According to the model, detailed kinetic studies were performed. We found that a 20-residue truncation of the C terminus extends the time until inorganic phosphate is generated and the time for arresting protein folding in the central cavity, i.e. the lifetime of the first rate-limiting step in the functional cycle, to an ∼5-s duration. These results suggest that the integrity of the C-terminal region facilitates the transition from the first to the second rate-limiting state.
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U2 - 10.1074/jbc.M804090200
DO - 10.1074/jbc.M804090200
M3 - Article
C2 - 18583344
AN - SCOPUS:53049084967
VL - 283
SP - 23931
EP - 23939
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 35
ER -