Colloquium

E. coli is a rod-shaped bacterium that grows and divides into two equivalent daughter cells. One mechanism that regulates the central placement of the division site is the Min-protein system, which prevents division near the cell ends. A surprising discovery in recent years is that the Min system is an oscillator involving wholesale shifts of proteins from one end of the cell to the other. I will present a model of the Min system, using only known properties of the proteins, which reproduces the formation of a ring of MinE proteins, polar growth of the MinD end caps, dependence of the oscillation period on protein concentrations, and the "zebra stripe" oscillations in filamentous cells. Finally, I will discuss the physiological significance of the Min system in light of these results.