Gearing up molecular rotary motors

Science ◽  
2017 ◽  
Vol 356 (6341) ◽  
pp. 906-907 ◽  
Author(s):  
Massimo Baroncini ◽  
Alberto Credi
Keyword(s):  
Rotary Motors

scholarly journals Coexistence of Two Chiral Helices Produces Kink Translation in Spiroplasma Swimming

2020 ◽  
Vol 202 (8) ◽  
Author(s):  
Daisuke Nakane ◽  
Tatsuro Ito ◽  
Takayuki Nishizaka
Keyword(s):  
Cell Body ◽  
The Body ◽  
Structural Basis ◽  
Helical Structures ◽  
Content Type ◽  
Carbonyl Cyanide ◽  
Rotary Motors ◽  
Propulsion Force ◽  
Swimming Bacteria ◽  
The Right

ABSTRACT The mechanism underlying Spiroplasma swimming is an enigma. This small bacterium possesses two helical shapes with opposite-handedness at a time, and the boundary between them, called a kink, travels down, possibly accompanying the dual rotations of these physically connected helical structures, without any rotary motors such as flagella. Although the outline of dynamics and structural basis has been proposed, the underlying cause to explain the kink translation is missing. We here demonstrated that the cell morphology of Spiroplasma eriocheiris was fixed at the right-handed helix after motility was stopped by the addition of carbonyl cyanide 3-chlorophenylhydrazone (CCCP), and the preferential state was transformed to the other-handedness by the trigger of light irradiation. This process coupled with the generation and propagation of the artificial kink, presumably without any energy input through biological motors. These findings indicate that the coexistence of two chiral helices is sufficient to propagate the kink and thus to propel the cell body. IMPORTANCE Many swimming bacteria generate a propulsion force by rotating helical filaments like a propeller. However, the nonflagellated bacteria Spiroplasma spp. swim without the use of the appendages. The tiny wall-less bacteria possess two chiral helices at a time, and the boundary called a kink travels down, possibly accompanying the dual rotations of the helices. To solve this enigma, we developed an assay to determine the handedness of the body helices at the single-wind level, and demonstrated that the coexistence of body helices triggers the translation of the kink and that the cell body moves by the resultant cell bend propagation. This finding provides us a totally new aspect of bacterial motility, where the body functions as a transformable screw to propel itself forward.

scholarly journals Basics of the electropiezoelasticity theory of piezoelectric motors with linear and rotary motion

2018 ◽  
Vol 67 (4) ◽  
pp. 149-168
Author(s):  
Włodzimierz Przyborowski
Keyword(s):  
Piezoelectric Effect ◽  
Rotary Motion ◽  
Electric Motors ◽  
Motion Equations ◽  
Piezoelectric Motors ◽  
Rotary Motors ◽  
General Mathematical Model ◽  
Linear Movement ◽  
Single Field ◽  
Constitutive Parameters

The paper presents the basics of the theory of electropiezoelasticity and adaptation of this theory to description of the simplest electromechanical converters − piezoelectric type electric motors. Because piezoelectricity and elasticity are coupled by complex piezoelasticity constitutive compounds, the formulation of a general mathematical model for these motors is not possible. Therefore, equations for structurally simple piezoelectric motors with linear and rotational motion have been formulated in the paper. Motors with linear movement are characterized by a flat or tube form. Rotary motors, on the other hand, have a cylindrical or disc-shaped form. The electric field, in the adopted forms of piezoelectric motors generating a piezoelectric effect, is a single-field perpendicular to the direction of motion. The determined equations could be simplified by reduction of some constitutive parameters, but it requires a detailed analysis of material compounds and consideration in the interactions of forces and torques in these motors, also strong piezoelectric stresses, which determine a specific kinetics. Keywords: piezoelectric motors with translational and rotary motion, equations of electric-piezoelasticity.

ATP Synthases and Bacterial Flagella Rotary Motors

Bioenergetics ◽  
2013 ◽  
pp. 197-220 ◽  
Author(s):  
David G. Nicholls ◽  
Stuart J. Ferguson
Keyword(s):  
Bacterial Flagella ◽  
Rotary Motors ◽  
Atp Synthases

Smart Grid-Integrated Electric Vehicle Charging Infrastructure

2022 ◽  
pp. 1-24
Author(s):  
Isa S. Qamber ◽  
Mohamed Y. Alhamad
Keyword(s):  
Electric Vehicle ◽  
Fossil Fuels ◽  
Electrical Energy ◽  
Charging Infrastructure ◽  
Electric Vehicle Charging ◽  
Proposed Model ◽  
Rotary Motors ◽  
The Cost ◽  
Efficiency And Reliability

The movements for any type of electric vehicle (EV) can be powered by wheels or driven by rotary motors. EVs derive their power from various sources, including fossil fuels. In the long term, reducing the cost of electrically powered vehicles (EDV) is seen as an essential ingredient to increase consumer acceptance. In addition, it aims to reduce the weight and volume of EDV. Moreover, the focus is on improving the performance, efficiency, and reliability of the EDV. The development of innovative modules is important when the acceleration of production and marketing needs to be improved. Consumers are looking for the production and transmission of electrical energy. This contributes to a greener environment. One of the most important parts of an EV is its battery. A proposed model presented in this chapter considers several parameters: solar radiation (PV panels), EV backup battery, and main charger. The model allows energy storage to be developed efficiently.

scholarly journals Design and Experiments of a Piezoelectric Motor Using Three Rotating Mode Actuators

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5184 ◽  
Author(s):  
Roland Ryndzionek ◽  
Łukasz Sienkiewicz ◽  
Michał Michna ◽  
Filip Kutt
Keyword(s):  
Numerical Analysis ◽  
Traveling Wave ◽  
Laser Interferometry ◽  
Experimental Tests ◽  
Impedance Analysis ◽  
Piezoelectric Motor ◽  
Resonant Frequencies ◽  
Rotary Motors ◽  
The Individual ◽  
Geometrical Dimensions

This paper represents a numerical and experimental investigation of the multicell piezoelectric motor. The proposed design consists of three individual cells that are integrated into the stator, double rotor, and a preload system combined into a symmetrical structure of the motor. Each of the cells is characterized by a traveling wave and rotating mode motor. A finite element numerical analysis is carried out to obtain optimal geometrical dimensions of the individual cell in terms of generated vibrations and resonant frequencies of the structure. The results of the numerical analysis are compared with analytical calculations based on the equivalent circuit theory. Experimental tests are also presented, including laser interferometry measurements of vibrations generated at the surface of the stator, impedance analysis, as well as measurements of mechanical characteristics of the complete motor. The final stage of the study concludes that the presented motor can provide relatively high torque compared with other traveling wave rotary motors.

scholarly journals Structure and function of the archaeal response regulator CheY

2018 ◽  
Vol 115 (6) ◽  
pp. E1259-E1268 ◽  
Author(s):  
Tessa E. F. Quax ◽  
Florian Altegoer ◽  
Fernando Rossi ◽  
Zhengqun Li ◽  
Marta Rodriguez-Franco ◽  
...  
Keyword(s):  
Environmental Changes ◽  
Response Regulator ◽  
Specific Interaction ◽  
Adaptor Protein ◽  
Structural Difference ◽  
Central Feature ◽  
Chemical Gradients ◽  
Rotary Motors ◽  
And Function ◽  
Chemotaxis System

Motility is a central feature of many microorganisms and provides an efficient strategy to respond to environmental changes. Bacteria and archaea have developed fundamentally different rotary motors enabling their motility, termed flagellum and archaellum, respectively. Bacterial motility along chemical gradients, called chemotaxis, critically relies on the response regulator CheY, which, when phosphorylated, inverses the rotational direction of the flagellum via a switch complex at the base of the motor. The structural difference between archaellum and flagellum and the presence of functional CheY in archaea raises the question of how the CheY protein changed to allow communication with the archaeal motility machinery. Here we show that archaeal CheY shares the overall structure and mechanism of magnesium-dependent phosphorylation with its bacterial counterpart. However, bacterial and archaeal CheY differ in the electrostatic potential of the helix α4. The helix α4 is important in bacteria for interaction with the flagellar switch complex, a structure that is absent in archaea. We demonstrated that phosphorylation-dependent activation, and conserved residues in the archaeal CheY helix α4, are important for interaction with the archaeal-specific adaptor protein CheF. This forms a bridge between the chemotaxis system and the archaeal motility machinery. Conclusively, archaeal CheY proteins conserved the central mechanistic features between bacteria and archaea, but differ in the helix α4 to allow binding to an archaellum-specific interaction partner.

scholarly journals Metastable asymmetrical structure of a shaftless V1 motor

2019 ◽  
Vol 5 (1) ◽  
pp. eaau8149 ◽  
Author(s):  
Shintaro Maruyama ◽  
Kano Suzuki ◽  
Motonori Imamura ◽  
Hikaru Sasaki ◽  
Hideyuki Matsunami ◽  
...  
Keyword(s):  
High Speed ◽  
Asymmetric Structure ◽  
Wild Type ◽  
Strong Constraint ◽  
Force Microscopy ◽  
X Ray Crystallography ◽  
Transition Mechanism ◽  
Asymmetrical Structure ◽  
Crown Structure ◽  
Rotary Motors

V1-ATPase is an ATP-driven rotary motor that is composed of a ring-shaped A3B3 complex and a central DF shaft. The nucleotide-free A3B3 complex of Enterococcus hirae, composed of three identical A1B1 heterodimers, showed a unique asymmetrical structure, probably due to the strong binding of the N-terminal barrel domain, which forms a crown structure. Here, we mutated the barrel region to weaken the crown, and performed structural analyses using high-speed atomic force microscopy and x-ray crystallography of the mutant A3B3. The nucleotide-free mutant A3B3 complex had a more symmetrical open structure than the wild type. Binding of nucleotides produced a closely packed spiral-like structure with a disrupted crown. These findings suggest that wild-type A3B3 forms a metastable (stressed) asymmetric structure composed of unstable A1B1 conformers due to the strong constraint of the crown. The results further the understanding of the principle of the cooperative transition mechanism of rotary motors.

Analysis of a mechanism with redundant drive for antenna pointing

2016 ◽  
Vol 231 (2) ◽  
pp. 229-239 ◽  
Author(s):  
Xin Li ◽  
Xilun Ding ◽  
Gregory S Chirikjian
Keyword(s):  
Inverse Kinematics ◽  
Parallel Mechanism ◽  
Numerical Examples ◽  
Pointing Device ◽  
Key Factor ◽  
Rotary Motors ◽  
Redundantly Actuated ◽  
Pointing Accuracy ◽  
Forward And Inverse Kinematics ◽  
Redundant Drive

Orientation accuracy is a key factor in the design of mechanisms for antenna pointing. Our design uses a redundantly actuated parallel mechanism which may provide an effective way to solve this problem, and even can increase its payload capability and reliability. The presented mechanism can be driven by rotary motors fixed on the base to reduce the inertia of the moving parts and to lower the power consumption. The mechanism is redundantly actuated by three arms, and is used as a two-dimensional antenna tracking and pointing device. Both the forward and inverse kinematics are investigated to find all the possible solutions. Detailed characters of the platform are analyzed to demonstrate the advantages in eliminating singularities and improving pointing accuracy. A method of calculating the overconstrained orientational error is also proposed based on the differential kinematics. All the methods are verified by numerical examples.

scholarly journals Torque Generation Mechanism of ATP Synthase and Other Rotary Motors

2009 ◽  
Vol 96 (3) ◽  
pp. 8a-9a
Author(s):  
John H. Miller ◽  
Vijayanand Vajrala ◽  
Hans L. Infante ◽  
James R. Claycomb
Keyword(s):  
Atp Synthase ◽  
Generation Mechanism ◽  
Torque Generation ◽  
Rotary Motors
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