Coupled rotation within single F0F1 enzyme complexes during ATP synthesis or hydrolysis.
F0F1 ATP synthases are the smallest rotary motors in nature and work as ATP factories in bacteria, plants and animals. Here we report on the first observation of intersubunit rotation in fully coupled single F0F1 molecules during ATP synthesis or hydrolysis. We investigate the Na+-translocating ATP synthase of Propionigenium modestum specifically labeled by a single fluorophore at one c subunit using polarization-resolved confocal microscopy. Rotation during ATP synthesis was observed with the immobilized enzyme reconstituted into proteoliposomes after applying a diffusion potential, but not with a Na+ concentration gradient alone. During ATP hydrolysis, stepwise rotation of the labeled c subunit was found in the presence of 2 mM NaCl, but not without the addition of Na+ ions. Moreover, upon the incubation with the F0-specific inhibitor dicyclohexylcarbodiimide the rotation was severely inhibited.
Kaim
Georg
G
Institute of Microbiology, ETH Zürich, Schmelzbergstrasse 7, CH-8092, Zürich, Switzerland.
Prummer
Michael
M
Sick
Beate
B
Zumofen
Gert
G
Renn
Alois
A
Wild
Urs P
UP
Dimroth
Peter
P
D000255:Adenosine Triphosphate / Q000737:chemistry* / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000187:drug effects / Q000235:genetics; D005456:Fluorescent Dyes; D005673:Fusobacterium / Q000201:enzymology; D006868:Hydrolysis; D008081:Liposomes / Q000737:chemistry; D046911:Macromolecular Substances; D018613:Microscopy, Confocal; D008958:Models, Molecular; D020409:Molecular Motor Proteins / Q000737:chemistry / Q000187:drug effects / Q000235:genetics; D016297:Mutagenesis, Site-Directed; D006180:Proton-Translocating ATPases / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000235:genetics; D012399:Rotation; D012964:Sodium / Q000737:chemistry / Q000494:pharmacology
D004791:Enzyme Inhibitors; D004800:Enzymes, Immobilized; D005456:Fluorescent Dyes; D008081:Liposomes; D046911:Macromolecular Substances; D020409:Molecular Motor Proteins; D000255:Adenosine Triphosphate; D012964:Sodium; D006180:Proton-Translocating ATPases