Journal ArticleDOI
Direct observation of the rotation of F1-ATPase
TLDR
It is shown that a single molecule of F1-ATPase acts as a rotary motor, the smallest known, by direct observation of its motion by attaching a fluorescent actin filament to the γ-subunit as a marker, which enabled us to observe this motion directly.Abstract:
Cells employ a variety of linear motors, such as myosin, kinesin and RNA polymerase, which move along and exert force on a filamentous structure. But only one rotary motor has been investigated in detail, the bacterial flagellum (a complex of about 100 protein molecules). We now show that a single molecule of F1-ATPase acts as a rotary motor, the smallest known, by direct observation of its motion. A central rotor of radius approximately 1 nm, formed by its gamma-subunit, turns in a stator barrel of radius approximately 5nm formed by three alpha- and three beta-subunits. F1-ATPase, together with the membrane-embedded proton-conducting unit F0, forms the H+-ATP synthase that reversibly couples transmembrane proton flow to ATP synthesis/hydrolysis in respiring and photosynthetic cells. It has been suggested that the gamma-subunit of F1-ATPase rotates within the alphabeta-hexamer, a conjecture supported by structural, biochemical and spectroscopic studies. We attached a fluorescent actin filament to the gamma-subunit as a marker, which enabled us to observe this motion directly. In the presence of ATP, the filament rotated for more than 100 revolutions in an anticlockwise direction when viewed from the 'membrane' side. The rotary torque produced reached more than 40 pN nm(-1) under high load.read more
Citations
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Journal ArticleDOI
Synthetic molecular motors and mechanical machines.
TL;DR: The exciting successes in taming molecular-level movement thus far are outlined, the underlying principles that all experimental designs must follow, and the early progress made towards utilizing synthetic molecular structures to perform tasks using mechanical motion are highlighted.
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Artificial Molecular Machines.
TL;DR: The aim of this review is to present a unified view of the field of molecular machines by focusing on past achievements, present limitations, and future perspectives.
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The 26S Proteasome: A Molecular Machine Designed for Controlled Proteolysis
TL;DR: In eukaryotic cells, most proteins in the cytosol and nucleus are degraded via the ubiquitin-proteasome pathway, and the 26S proteasome is a 2-MDa molecular machine built from approximately 31 different subunits, which catalyzes protein degradation.
Journal ArticleDOI
Atomic-Level Characterization of the Structural Dynamics of Proteins
David E. Shaw,David E. Shaw,Paul Maragakis,Kresten Lindorff-Larsen,Stefano Piana,Ron O. Dror,Michael P. Eastwood,Joseph A. Bank,John M. Jumper,John K. Salmon,Yibing Shan,Willy Wriggers +11 more
TL;DR: Simulation of the folding of a WW domain showed a well-defined folding pathway and simulation of the dynamics of bovine pancreatic trypsin inhibitor showed interconversion between distinct conformational states.
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Light-driven monodirectional molecular rotor
TL;DR: In this article, the authors report repetitive, monodirectional rotation around a central carbon-carbon double bond in a chiral, helical alkene, with each 360° rotation involving four discrete isomerization steps activated by ultraviolet light or a change in the temperature of the system.
References
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Coupling of Phosphorylation to Electron and Hydrogen Transfer by a Chemi-Osmotic type of Mechanism
TL;DR: Coupling of Phosphorylation to Electron and Hydrogen Transfer by a Chemi-Osmotic type of Mechanism is described.
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Structure at 2.8 A resolution of F1-ATPase from bovine heart mitochondria.
TL;DR: The crystal structure of bovine mitochondrial F1-ATPase determined at 2.8 Å resolution supports a catalytic mechanism in intact ATP synthase in which the three catalytic subunits are in different states of the catalytic cycle at any instant.
Journal ArticleDOI
Direct observation of kinesin stepping by optical trapping interferometry
TL;DR: It is found that kinesin moves with 8-nm steps, similar to biological motors that move with regular steps.
Journal ArticleDOI
Single myosin molecule mechanics: piconewton forces and nanometre steps
TL;DR: A new in vitro assay using a feedback enhanced laser trap system allows direct measurement of force and displacement that results from the interaction of a single myosin molecule with a single suspended actin filament.
Journal ArticleDOI
The binding change mechanism for ATP synthase — Some probabilities and possibilities
TL;DR: Conformational changes and catalysis, the uniqueness of the ATP synthase structure and the role of unfolded protein structure in mechanism are discussed.