Bacterial Chemotaxis: Then and Now

From Q-bio

Bacteria are self-replicating machines about one micron in diameter. Many swim by rotating long, thin, helical filaments that arise at one or more points on the cell surface. Each filament is driven at its base by a rotary motor only 45 nm in diameter made from about 20 different kinds of parts. Control of the direction of rotation of such flagellar motors is the basis for the behavioral response, e.g., for the ability of cells to swim up spatial gradients of chemical attractants. The best-studied organism is Escherichia coli, that lives in your gut. I will review the history of this subject, tell you about some of the physics that E. coli knows, outline the signal transduction pathway that links its chemoreceptors to the flagella, and describe some of the experimental and theoretical work that has been done to probe its secrets.