Target type: biologicalprocess
Cell motility due to the motion of one or more bacterial-type flagella. A bacterial-type flagellum is a motor complex composed of an extracellular helical protein filament coupled to a rotary motor embedded in the cell envelope. [GOC:cilia, GOC:krc, GOC:mah]
Bacterial flagella are complex, helical protein filaments that extend from the cell surface and are responsible for bacterial motility. They are driven by a rotary motor embedded in the cell envelope, powered by a proton motive force. The flagellar motor consists of a stator, which is anchored in the cell wall, and a rotor, which is connected to the flagellar filament. The stator is composed of Mot proteins, which bind protons and use their electrochemical potential to rotate the rotor. The rotor is made up of Fli proteins, which interact with the stator to generate torque.
The flagellar filament is a helical polymer of flagellin protein subunits. The filament is assembled at its distal tip by the addition of new flagellin subunits. The filament is hollow, and its internal channel allows for the passage of the flagellar hook, which connects the filament to the rotor.
The direction of rotation of the flagellar motor determines the direction of bacterial movement. When the motor rotates counterclockwise, the flagella bundle together, propelling the bacterium in a straight line. This is known as "run" motility. When the motor rotates clockwise, the flagella separate, causing the bacterium to tumble randomly. This is known as "tumble" motility.
The bacterium uses a combination of runs and tumbles to navigate its environment. When a bacterium encounters a favorable environment, it continues to run in that direction. When it encounters an unfavorable environment, it tumbles until it finds a more favorable direction. This process, known as chemotaxis, allows bacteria to move towards attractants and away from repellents.
Flagellar motility is essential for bacterial survival. It allows bacteria to access nutrients, avoid predators, and colonize new environments. Flagellar motility is also important for the pathogenesis of many bacterial diseases. For example, the flagella of Salmonella enterica are essential for its ability to invade the intestinal epithelium.
The flagellar motor is a highly efficient and complex molecular machine. Its design has inspired the development of new technologies, such as microfluidic devices and miniature motors. The study of bacterial flagellar motility has also provided insights into the evolution and function of cellular motility in general.'
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| Protein | Definition | Taxonomy |
|---|---|---|
| DNA-directed RNA polymerase subunit beta | A DNA-directed RNA polymerase subunit beta that is encoded in the genome of Escherichia coli K-12. [PRO:DNx, UniProtKB:P0A8V2] | Escherichia coli K-12 |
| DNA-directed RNA polymerase subunit beta' | A DNA-directed RNA polymerase subunit beta that is encoded in the genome of Escherichia coli K-12. [PRO:DNx, UniProtKB:P0A8T7] | Escherichia coli K-12 |
| DNA-directed RNA polymerase subunit omega | A DNA-directed RNA polymerase subunit omega that is encoded in the genome of Escherichia coli K-12. [PRO:DNx, UniProtKB:P0A800] | Escherichia coli K-12 |
| DNA-directed RNA polymerase subunit alpha | A DNA-directed RNA polymerase subunit alpha that is encoded in the genome of Escherichia coli K-12. [PRO:DNx, UniProtKB:P0A7Z4] | Escherichia coli K-12 |
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| quinacrine | quinacrine : A member of the class of acridines that is acridine substituted by a chloro group at position 6, a methoxy group at position 2 and a [5-(diethylamino)pentan-2-yl]nitrilo group at position 9. Quinacrine: An acridine derivative formerly widely used as an antimalarial but superseded by chloroquine in recent years. It has also been used as an anthelmintic and in the treatment of giardiasis and malignant effusions. It is used in cell biological experiments as an inhibitor of phospholipase A2. | acridines; aromatic ether; organochlorine compound; tertiary amino compound | antimalarial; EC 1.8.1.12 (trypanothione-disulfide reductase) inhibitor |
| rifamycin sv | rifamycin SV : A member of the class of rifamycins that exhibits antibiotic and antitubercular properties. rifamycin SV: RN given refers to parent cpd; structure in Merck Index, 9th ed, #8009 | acetate ester; cyclic ketal; lactam; macrocycle; organic heterotetracyclic compound; polyphenol; rifamycins | antimicrobial agent; antitubercular agent; bacterial metabolite |