The role of subunit epsilon in the catalysis and regulation of FOF1-ATP synthase.
The regulation of ATP synthase activity is complex and involves several distinct mechanisms. In bacteria and chloroplasts, subunit epsilon plays an important role in this regulation, (i) affecting the efficiency of coupling, (ii) influencing the catalytic pathway, and (iii) selectively inhibiting ATP hydrolysis activity. Several experimental studies indicate that the regulation is achieved through large conformational transitions of the alpha-helical C-terminal domain of subunit epsilon that occur in response to membrane energization, change in ATP/ADP ratio or addition of inhibitors. This review summarizes the experimental data obtained on different organisms that clarify some basic features as well as some molecular details of this regulatory mechanism. Multiple functions of subunit epsilon, its role in the difference between the catalytic pathways of ATP synthesis and hydrolysis and its influence on the inhibition of ATP hydrolysis by ADP are also discussed.
Feniouk
Boris A
BA
ATP System Project, Exploratory Research for Advanced Technology, Japan Science and Technology Corporation (JST), 5800-3 Nagatsuta, Midori-ku, Yokohama 226-0026, Japan. fboris@bio.res.titech.ac.jp
Suzuki
Toshiharu
T
Yoshida
Masasuke
M
D000595:Amino Acid Sequence; D000818:Animals; D001419:Bacteria / Q000201:enzymology; D002384:Catalysis; D004789:Enzyme Activation; D006801:Humans; D006868:Hydrolysis; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010944:Plants / Q000201:enzymology; D011487:Protein Conformation; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D006180:Proton-Translocating ATPases / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D025262:Vacuolar Proton-Translocating ATPases / Q000235:genetics / Q000378:metabolism
D021122:Protein Subunits; D025262:Vacuolar Proton-Translocating ATPases; D006180:Proton-Translocating ATPases