title: Axle-less F1-ATPase rotates in the correct direction.
abstract: F1-adenosine triphosphatase (ATPase) is an ATP-driven rotary molecular motor in which the central gamma subunit rotates inside a cylinder made of three alpha and three beta subunits alternately arranged. The rotor shaft, an antiparallel alpha-helical coiled coil of the amino and carboxyl termini of the gamma subunit, deeply penetrates the central cavity of the stator cylinder. We truncated the shaft step by step until the remaining rotor head would be outside the cavity and simply sat on the concave entrance of the stator orifice. All truncation mutants rotated in the correct direction, implying torque generation, although the average rotary speeds were low and short mutants exhibited moments of irregular motion. Neither a fixed pivot nor a rigid axle was needed for rotation of F1-ATPase.
authors.affiliation: Department of Physics, Faculty of Science and Engineering, Waseda University, Shinjuku-ku, Tokyo 169-8555, Japan.
authors.forename: Shou
authors.initials: S
authors.lastname: Furuike
authors.forename: Mohammad Delawar
authors.initials: MD
authors.lastname: Hossain
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Maki
authors.forename: Kengo
authors.initials: K
authors.lastname: Adachi
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Suzuki
authors.forename: Ayako
authors.initials: A
authors.lastname: Kohori
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Itoh
authors.forename: Masasuke
authors.initials: M
authors.lastname: Yoshida
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Kinosita
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D006868:Hydrolysis; D008863:Microspheres; D020409:Molecular Motor Proteins / Q000737:chemistry* / Q000378:metabolism; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000737:chemistry; D009154:Mutation; D011487:Protein Conformation; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism; D006180:Proton-Translocating ATPases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D012399:Rotation; D019415:Torque
chemical_list: D020409:Molecular Motor Proteins; D050505:Mutant Proteins; D021122:Protein Subunits; D000255:Adenosine Triphosphate; D006180:Proton-Translocating ATPases