
%0 Journal Article
%A Hisabori, Toru 
%A Bald, Dirk 
%A Noji, Hiroyuki 
%A Yoshida, Masasuke 
%A Suzuki, Toshiharu 
%A Konno, Hiroki 
%T Thiol modulation of the chimeric ATP synthase complex of bacterial F1 containing the regulatory region of the gamma subunit of chloroplast ATP synthase
%J Science Access
%D 2001/01/01
%V 3
%N 1
%P -
%K 
%R https://doi.org/10.1071/SA0403305
%U https://www.publish.csiro.au/paper/SA0403305 
%X 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. 
