title: The oligomeric subunit C rotor in the fo sector of ATP synthase: unresolved questions in our understanding of function.
abstract: We have proposed a model for the oligomeric c-rotor of the F(o) sector of ATP synthase and its interaction with subunit a during H+-transport driven rotation. The model is based upon the solution structure of monomeric subunit c, determined by NMR, and an extensive series of cross-linking distance constraints between c subunits and between subunits c and a. To explain the complete set of cross-linking data, we have suggested that the second transmembrane helix rotates during its interaction with subunit a in the course of the H+-translocation cycle. The H+-transport coupled rotation of this helix is proposed to drive the stepwise movement of the c-oligomeric rotor. The model is testable and provides a useful framework for addressing questions raised by other experiments.
authors.affiliation: Department of Biomolecular Chemistry, University of Wisconsin Medical School, 1300 University Avenue, Madison, Wisconsin 53706, USA. rhfillin@facstaff.wisc.edu
authors.forename: R H
authors.initials: RH
authors.lastname: Fillingame
authors.forename: W
authors.initials: W
authors.lastname: Jiang
authors.forename: O Y
authors.initials: OY
authors.lastname: Dmitriev
mesh_terms: D025243:Bacterial Proton-Translocating ATPases / Q000737:chemistry / Q000378:metabolism; D018360:Crystallography, X-Ray; D009682:Magnetic Resonance Spectroscopy; D025261:Mitochondrial Proton-Translocating ATPases / Q000737:chemistry* / Q000378:metabolism*; D008958:Models, Molecular; D021122:Protein Subunits; D018892:Proton-Motive Force
chemical_list: D021122:Protein Subunits; D025243:Bacterial Proton-Translocating ATPases; C474451:F1F0-ATP synthase; D025261:Mitochondrial Proton-Translocating ATPases