
TY  - JOUR
A1  - Hisabori, Toru 
A1  - Bald, Dirk 
A1  - Noji, Hiroyuki 
A1  - Yoshida, Masasuke 
A1  - Suzuki, Toshiharu 
A1  - Konno, Hiroki 
T1  - Thiol modulation of the chimeric ATP synthase complex of bacterial F1 containing the regulatory region of the gamma subunit of chloroplast ATP synthase
JF  - Science Access
JO  - 
Y1  - 2001
VL  - 3
IS  - 1
SP  - 
EP  - 
KW  - 
UR  - https://doi.org/10.1071/SA0403305 
N2  - The ATP synthase of chloroplasts (CFoCF1) is activated by the proton gradient across the thylakoid membrane and modulated by the reduction of a disulfide bridge in the g subunit (thiol modulation). The cysteines involved in this regulation are located in an additional amino acid stretch (the regulatory region) of CF1-g subunit. In the solubilized CF1 reduction of the disulfide bond in g causes elicitation of the latent ATP hydrolyzing activity. We identified the important sequences for the regulation from the study of the reconstituted complex, which contains the mutant g subunit with a partial deletion of this regulatory region.  In addition, we constructed a mutant F1-ATPase a3b3g sub-complex from a thermophilic bacterium in which the central region of the g subunit was replaced by the homologous region from spinach CF1 g subunit including the regulatory region. ATP hydrolysis activity of this mutant showed that thiol modulation and was inhibited by the e subunit from CF1, but not by TF1-e. Using a single-molecule observation technique, we investigated ATP hydrolysis-coupled rotation of the g subunit and the redox regulation of this rotation. The e subunit of ATP synthase is a well-known intrinsic inhibitor subunit. We recently elucidated the relationship between the conformational change of this subunit and the function. The results showed that the interaction between the C-terminal a-helix of e and the DELSEED region of b is very important for the inhibition.  Based on these findings, I will discuss on the regulation system for ATP synthase. 
ER  -

