Related Experiment Video
Updated: Jul 6, 2026
07:59
Investigating Flagella-Driven Motility in Escherichia coli by Applying Three Established Techniques in a Series
Published on: May 10, 2020
The bacterial flagellar switch complex is getting more complex.
Galit N Cohen-Ben-Lulu1, Noreen R Francis, Eyal Shimoni
1Department of Biological Chemistry, The Weizmann Institute of Science, Rehovot, Israel.
The EMBO Journal
|March 14, 2008
Summary
Researchers discovered fumarate reductase (FRD) is crucial for bacterial flagellar rotation and assembly. This respiratory enzyme unexpectedly functions in flagellar switching even under aerobic conditions.
Area of Science:
- Microbiology
- Molecular Biology
- Biochemistry
Background:
- The bacterial flagellar switch controls rotation direction, vital for chemotaxis.
- Its precise mechanism has been a long-standing mystery in microbial motility.
Purpose of the Study:
- To elucidate the molecular mechanism of the bacterial flagellar switch.
- To identify novel proteins involved in flagellar assembly and function.
Main Methods:
- Biochemical assays to detect protein-protein interactions.
- Analysis of flagellar assembly and rotation in the presence/absence of specific proteins and compounds.
Main Results:
- The membrane-bound fumarate reductase (FRD) was found to associate with the flagellar switch complex.
- FRD forms a 1:1 complex with the switch protein FliG, essential for flagellar assembly and rotation direction.
- Fumarate influences flagellar rotation direction via FRD, indicating a role beyond anaerobic respiration.
Conclusions:
- Fumarate reductase (FRD) is a newly identified key component of the bacterial flagellar switch machinery.
- FRD plays an unexpected role in flagellar assembly and function under aerobic conditions, challenging previous understanding of its function.
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...
01:57Protein Complexes with Interchangeable Parts
Groups of proteins may form a complex where each protein in this complex has a different role in the overall execution of the complex’s function. Often some of the proteins in the complex can be replaced by a closely related variant to give a complex that contains many of the same components yet is functionally distinct.
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to...
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to...
01:57Protein Complexes with Interchangeable Parts
Groups of proteins may form a complex where each protein in this complex has a different role in the overall execution of the complex’s function. Often some of the proteins in the complex can be replaced by a closely related variant to give a complex that contains many of the same components yet is functionally distinct.
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to...
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to...
01:27Chemotaxis in E. coli
Chemotaxis in Escherichia coli is a sensory-driven motility mechanism that enables bacteria to navigate chemical gradients, moving toward beneficial environments while avoiding harmful conditions. This process relies on a signal transduction system integrating external chemical cues with flagellar motor control.Chemoreceptors and Signal DetectionE. coli detects chemical gradients through methyl-accepting chemotaxis proteins (MCPs), which are membrane-bound chemoreceptors that sense attractants...
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...
01:24Microtubules 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...