Rotary molecular motor

Coming, P.A. (2002). Thermoeconomics beyond the second law. J. Bioeconom., 4, 57-88 Everett, D.H. (1959). An Introduction to Chemical Thermodynamics. Longmans, London Kinosita, K., Yasuda, R., Noji, H. and Adachi, K. (2000). A rotary molecular motor that can work at near 100% efficiency. Philos. Trans. Act. Royal Soc. London B, 355, 473—489. See also Proc. Biochem. Soc. (2005) Meeting Mechanics of Bioenergetic Membrane Proteins Structures and... 

A unique feature of the F/V/A-ATPases is that they are rotary molecular motor enzymes. This has been shown by experiment for members of the F-and V-ATPase subfamilies and is generally assumed to be true for the closely related A-ATPases as well. The two enzymatic processes, ATP synthesis/hydrolysis and ion translocation, are coupled via a rotational motion of a central domain of the complex (the rotor) relative to a static domain (the stator). The A-, F-, and V-ATPases represent the smallest rotary motors found in the living cell so far. Most of what we know about the structure and mechanism of these microscopic energy converters comes from studies conducted with the F-ATPase. In the following review, current structural knowledge for all three members of the family of F-, V-,... 

Wilkens S (2005) Rotary molecular motors. Adv Protein Chem 71 345-382. 

This protein consists of two rotary molecular motors, F0 and F1 attached to a common shaft (known as the y subunit), each attempting to rotate in the opposite direction. The Fi motor uses the free energy of ATP hydrolysis to rotate in one direction whereas the Fo motor uses the energy stored in a transmembrane electrochemical gradient to turn in the opposite direction. Which motor wins (i.e., develops more torque) depends on cellular conditions. When F0 takes over, which is the normal... 

Fig. 4 A chemically driven rotary molecular motor able to achieve a 360° unidirectional rotation (a) the sequence of chemical reactions (b) a stylized representation of the motion...

Kelly TR, Cai X, Damkaci F, Panicker SB, Tu B, Bushell SM, Cornelia I, Piggott MJ, Salives R, Cavero M, Zhao Y, Jasmin S. Progress toward a rationally designed, chemically powered rotary molecular motor. J. Am. Chem. Soc. 2007 129 376-386. 

Chemo-Mechanical Coupling in the Rotary Molecular Motor Fi-ATPase... 

Fi-ATPase, a water-soluble portion of ATP synthase, has been predicted [1,2] and proved [3] to be an ATP-driven rotary molecular motor in which the central Y subunit rotates inside a hexameric cylinder made of alternately arranged three a and three P subunits [4]. When the rotor subunit y is rotated in reverse by the application of an external force, the motor turns into a generator and synthesizes ATP from ADP and inorganic phosphate (Pi) in the catalytic sites [5,6]. Fi is thus a reversible chemo-mechanical energy converter as its physiological role implies [7-11]. 

K. Kinosita, Jr., R. Yasuda, H. Noji, K. Adachi, A rotary molecular motor that can work at near 100% efficiency. Phil.Trans. R. Soc. Lond. B 355, 473-... 

Anabaena sensory rhodopsin (ASR, Fig. 10.2) [15, 16]—and a class [17, 18] of synthetic light-driven rotary molecular motors developed from chiral overcrowded alkenes [19], As further discussed below, verifying this analogy may have positive implications for the future design and construction of synthetic molecular motors. 

Anabaena Sensory Rhodopsin and Light-Driven Rotary Molecular Motors... 

PoUard MM, Klok M, Pijper D, Feringa BL (2007) Rate acceleration of light-driven rotary molecular motors. Adv Funct Mater 17 718-729... 

Furthermore, just as photochemistry is a clean way to cause a reaction, it may offer a clean way to cause a movement in a macroscopic object. As a matter of fact, this is an issue rarely adopted by natme, where direct conversion of light into mechanical energy is limited to a few cases in bacteria [16]. This does not preclude adopting this principle for artificial system. As an example, one may think of controlling and directing the Brownian motion of molecules in solution and to induce directional translational and rotary motion of molecules or of nano-objects. In other words, rotary and translational motors may be devised and used to power future nanodevices. For example, rotary molecular motors allow the transmission of motion in multicomponent systems as well as reaching out-of-equilibrium assemblies (see Fig. 11.5) [18]. 

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