The gamma subunit in chloroplast F(1)-ATPase can rotate in a unidirectional and counter-clockwise manner.
Rotation of the gamma subunit in chloroplast F(1)-ATPase (CF(1)) was investigated by using a single molecule observation technique, which is developed by Noji et al. to observe the rotation of a central gamma subunit portion in the alpha(3)beta(3)gamma sub-complex of F(1)-ATPase from thermophilic Bacillus PS3 (TF(1)) during ATP hydrolysis [Noji, H. et al. (1997) Nature 386, 299-302]. We used two cysteines of the gamma subunit (Cys-199 and Cys-205) of CF(1)-ATPase, which are involved in the regulation of this enzyme, to fix the fluorochrome-labeled actin filament. Then we successfully observed a unidirectional, counter-clockwise rotation of the actin filament with the fluorescent microscope indicating the rotation of the gamma subunit in CF(1)-ATPase. We conclude that the rotation of the gamma subunit in the F(1)-motor is a ubiquitous phenomenon in all F(1)-ATPases in prokaryotes as well as in eukaryotes.
Hisabori
T
T
Research Laboratory of Resources Utilization, Tokyo Institute of Technology, Nagatsuta 4259, Midori-ku, Yokohama, Japan. thisabor@res.titech.ac.jp
Kondoh
A
A
Yoshida
M
M
D008841:Actin Cytoskeleton / Q000378:metabolism; D000199:Actins / Q000378:metabolism; D002736:Chloroplasts / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D008856:Microscopy, Fluorescence; D011487:Protein Conformation; D006180:Proton-Translocating ATPases / Q000378:metabolism*; D012399:Rotation; D018724:Spinacia oleracea / Q000201:enzymology; D013997:Time Factors
D000199:Actins; D006180:Proton-Translocating ATPases