Related Experiment Video
Updated: Jun 20, 2026
06:08
Biophysical Characterization of Flagellar Motor Functions
Published on: January 18, 2017
Bacteria harness torque-induced buckling instability for flagellar wrapping
Takuro Kataoka1, Taiju Yoneda1,2, Daisuke Nakane3
1Ritsumeikan University, Department of Physical Sciences, Kusatsu, Shiga 525-8577, Japan.
Physical Review. E
|June 19, 2026
Summary
Bacteria use a novel buckling mechanism to wrap flagella for locomotion in viscous environments. This physically driven process is crucial for bacterial symbiosis and infection.
Area of Science:
- Biophysics
- Microbiology
- Cellular Mechanics
Background:
- Bacterial flagella enable motility, with recent discoveries revealing unique behaviors like flagellar wrapping.
- Flagellar wrapping allows bacteria to move like corkscrews in viscous or confined spaces, vital for symbiosis.
Purpose of the Study:
- Investigate the physical principles behind flagellar wrapping, a motor-induced buckling instability.
- Understand how bacteria transition flagella from extended to wrapped states for locomotion.
Main Methods:
- Combined macroscale physical experiments, numerical simulations, and scaling theory.
- Analyzed geometrically nonlinear deformation of helical flagellar filaments.
- Constructed a stability diagram using elastohydrodynamic scaling analysis.
Main Results:
- Demonstrated excellent quantitative agreement between experimental and numerical results.
- Highlighted the essential role of long-range hydrodynamic interactions in flagellar wrapping.
- Developed a stability diagram rationalizing the buckling boundary.
Conclusions:
- Bacteria likely exploit motor-induced buckling instability for flagellar wrapping.
- This mechanically driven process is fundamental to bacterial motility, symbiosis, and infection.
Related Concept Videos
01:18Flagella and Motility in Bacteria
Flagella are specialized, thread-like structures that extend from a bacteria's cell envelope. They play a crucial role in motility and chemotaxis. Their structural organization and functioning exemplify sophisticated biological engineering, enabling bacterial survival and adaptability in diverse environments.Structure of the FlagellumA bacterial flagellum consists of three key components: the filament, the hook, and basal body. The filament, a long, helical structure composed of repeating...
01:28Fimbriae, Pili, and Axial Filaments
Fimbriae and pili are specialized bacterial surface structures that play pivotal roles in adhesion, genetic exchange, and motility. Composed primarily of pilin protein, these hairlike appendages are crucial for bacterial survival and pathogenicity in various environments.Fimbriae: Adhesion and PathogenicityFimbriae are fine, filamentous structures measuring 2–10 nanometers in diameter and are densely distributed on the bacterial cell surface. They facilitate bacterial adhesion to abiotic...
01:29Cytoskeletal Proteins in Bacteria
Bacterial cells were initially considered simple, randomly organized structures lacking a cytoskeleton. However, the discovery of cytoskeleton homologs in bacteria led to the change of this opinion. Bacterial cytoskeletal filaments regulate the cell shape, cell polarity, cell division, and partitioning of plasmids during cell division. It was later discovered that bacterial cytoskeletal proteins, mainly actin and tubulin homologs, are diverse compared to their eukaryotic counterparts. On the...
01:39Mechanism of Filopodia Formation
Filopodia are thin, actin-rich cellular protrusions that play an important role in many fundamental cellular functions. They vary in their occurrence, length, and positioning in different cell types, suggesting their diverse roles.
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
01:31Mechanism of Lamellipodia Formation
Cells migrating in response to external stimuli form lamellipodia, which are thin membrane protrusions supported by a mesh of linked, branched, or unbranched actin filaments. These actin filaments interact with myosin motor proteins, creating the dynamic actomyosin complex within the cytoskeleton. Contractility, or the ability to generate contractile stress, is inherent to the actomyosin complex. It helps cells detect the stiffness of the surrounding ECM and exert contractile force for...
01:24Microtubules in Cell Motility
Microtubules are thick hollow cylindrical proteins that help form the cytoskeleton. Microtubules have varied roles in the cell. These filaments help form cellular appendages like cilia and flagella, which are responsible for locomotion. The cilia arise from basal bodies, separated from the main body by a membrane-like structure forming the transition zone. This zone is the gate for the entry of lipids and proteins, creating a unique composition of lipids and proteins in the ciliary membrane and...