Recent work has provided the detailed overall architecture and subunit composition of three subtypes of rotary ATPases. Composite models of F-type, V-type and A-type ATPases have been constructed by fitting high-resolution X-ray structures of individual components into electron microscopy derived envelopes of the intact enzymes. Electron cryo-tomography has provided new insights into the supra-molecular arrangement of eukaryotic ATP synthases within mitochondria. An inherent flexibility in rotary ATPases observed by different techniques suggests greater dynamics during operation than previously envisioned. The concerted movement of subunits within the complex might provide means of regulation and information transfer between distant parts of rotary ATPases thereby fine tuning these molecular machines to their cellular environment, while optimizing their efficiency.
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http://dx.doi.org/10.1016/j.sbi.2013.11.013 | DOI Listing |
Biomolecules
November 2024
Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita Osaka 565-0871, Japan.
Many bacteria swim in liquids and move over solid surfaces by rotating flagella. The bacterial flagellum is a supramolecular protein complex that is composed of about 30 different flagellar proteins ranging from a few to tens of thousands. Despite structural and functional diversities of the flagella among motile bacteria, the flagellum commonly consists of a membrane-embedded rotary motor fueled by an ion motive force across the cytoplasmic membrane, a universal joint, and a helical propeller that extends several micrometers beyond the cell surface.
View Article and Find Full Text PDFResearch (Wash D C)
December 2024
School of Medicine and Health, Harbin Institute of Technology, Harbin 150001, China.
Living microorganisms can perform directed migration for foraging in response to a chemoattractant gradient. We report a biomimetic strategy that rotary FF-ATPase (adenosine triphosphatase)-propelled flasklike colloidal motors exhibit positive chemotaxis resembling the chemotactic behavior of bacteria. The streamlined flasklike colloidal particles are fabricated through polymerization, expansion, surface rupture, and re-polymerizing nanoemulsions composed of triblock copolymers and ribose.
View Article and Find Full Text PDFMethods Mol Biol
December 2024
Department of Structural Biology, Max Planck Institute of Biophysics, Frankfurt am Main, Germany.
F-type Adenosine triphosphate (ATP) synthase is a membrane-bound macromolecular complex, which is responsible for the synthesis of ATP, the universal energy source in living cells. This enzyme uses the proton- or sodium-motive force to power ATP synthesis by a unique rotary mechanism and can also operate in reverse, ATP hydrolysis, to generate ion gradients across membranes. The FF-ATP synthases from bacteria consist of eight different structural subunits, forming a complex of ~550 kDa in size.
View Article and Find Full Text PDFMethods Mol Biol
December 2024
Centre de Biologie Structurale, Université de Montpellier, CNRS, INSERM, Montpellier, France.
The bacterial flagellar motor (BFM) is a rotary molecular machine that drives critical bacterial processes including motility, chemotaxis, biofilm formation, and infection. For over two decades, the bead assay, which measures the rotation of a microparticle attached to the flagellum of a surface-attached bacterium, has been instrumental in deciphering the motor's biophysical mechanisms. This technique has not only quantified the rotational speed and frequency of directional switching as a function of the viscous load on the flagellum but has also revealed the BFM's capacity for mechanosensitive speed modulation, adapting to environmental conditions.
View Article and Find Full Text PDFNano Lett
December 2024
Institute for Molecular Science, National Institutes of National Sciences, Okazaki, Aichi 444-8787, Japan.
Understanding the function of rotary molecular motors, such as rotary ATPases, relies on our ability to visualize single-molecule rotation. Traditional imaging methods often involve tagging those motors with nanoparticles (NPs) and inferring their rotation from the translational motion of NPs. Here, we report an approach using "two-faced" Janus NPs to directly image the rotation of a single V-ATPase from , an ATP-driven rotary ion pump.
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