title: Rotary ATPases: A New Twist to an Ancient Machine.
abstract: Rotary ATPases are energy-converting nanomachines found in the membranes of all living organisms. The mechanism by which proton translocation through the membrane drives ATP synthesis, or how ATP hydrolysis generates a transmembrane proton gradient, has been unresolved for decades because the structure of a critical subunit in the membrane was unknown. Electron cryomicroscopy (cryoEM) studies of two rotary ATPases have now revealed a hairpin of long, horizontal, membrane-intrinsic α-helices in the a-subunit next to the c-ring rotor. The horizontal helices create a pair of aqueous half-channels in the membrane that provide access to the proton-binding sites in the rotor ring. These recent findings help to explain the highly conserved mechanism of ion translocation by rotary ATPases.
authors.affiliation: Department of Structural Biology, Max Planck Institute of Biophysics, Max-von-Laue Strasse 3, 60438 Frankfurt am Main, Germany. Electronic address: Werner.Kuehlbrandt@biophys.mpg.de.
authors.forename: Werner
authors.initials: W
authors.lastname: Kühlbrandt
authors.affiliation: Department of Structural Biology, Max Planck Institute of Biophysics, Max-von-Laue Strasse 3, 60438 Frankfurt am Main, Germany.
authors.forename: Karen M
authors.initials: KM
authors.lastname: Davies
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D006801:Humans; D008958:Models, Molecular
chemical_list: D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases