Helix sliding in the stalk coiled coil of dynein couples ATPase and microtubule binding.
Coupling between ATPase and track binding sites is essential for molecular motors to move along cytoskeletal tracks. In dynein, these sites are separated by a long coiled coil stalk that must mediate communication between them, but the underlying mechanism remains unclear. Here we show that changes in registration between the two helices of the coiled coil can perform this function. We locked the coiled coil at three specific registrations using oxidation to disulfides of paired cysteine residues introduced into the two helices. These trapped ATPase activity either in a microtubule-independent high or low state, and microtubule binding activity either in an ATP-insensitive strong or weak state, depending on the registry of the coiled coil. Our results provide direct evidence that dynein uses sliding between the two helices of the stalk to couple ATPase and microtubule binding activities during its mechanochemical cycle.
Kon
Takahide
T
Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, Komaba 3-8-1, Tokyo 153-8902, Japan.
Imamula
Kenji
K
Roberts
Anthony J
AJ
Ohkura
Reiko
R
Knight
Peter J
PJ
Gibbons
I R
IR
Burgess
Stan A
SA
Sutoh
Kazuo
K
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D004023:Dictyostelium; D004398:Dyneins / Q000737:chemistry* / Q000378:metabolism*; D008124:Locomotion; D008870:Microtubules / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D017433:Protein Structure, Secondary; D015800:Protozoan Proteins / Q000737:chemistry* / Q000378:metabolism*
D015800:Protozoan Proteins; D000251:Adenosine Triphosphatases; D004398:Dyneins