Axle-less F1-ATPase rotates in the correct direction.
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.
Furuike
Shou
S
Department of Physics, Faculty of Science and Engineering, Waseda University, Shinjuku-ku, Tokyo 169-8555, Japan.
Hossain
Mohammad Delawar
MD
Maki
Yasushi
Y
Adachi
Kengo
K
Suzuki
Toshiharu
T
Kohori
Ayako
A
Itoh
Hiroyasu
H
Yoshida
Masasuke
M
Kinosita
Kazuhiko
K
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
D020409:Molecular Motor Proteins; D050505:Mutant Proteins; D021122:Protein Subunits; D000255:Adenosine Triphosphate; D006180:Proton-Translocating ATPases