An oscillating wave of proteins within the bacterium E. coli helps it divide precisely in half.


Video transcript

Cellular division is fundamental for life. But how do cells know where their middle is so they can divide precisely in half? Do they use little measuring sticks?

The tiny bacterium named E. coli uses a biochemical trick: A wave-like oscillation of three coordinated proteins. The star of this process is MinC, a protein that can prevent reproduction from taking place.

The trick for the cell is to keep MinC away from its middle when the cell is ready to divide. The cell does this with two helper molecules. One is MinD, which binds to the cell membrane and recruits MinC to join it there. The MinD-MinC complexes also have a pushy friend, named MinE. MinE boots MinD and MinC off the membrane.

The MinDs and MinCs rush around in search of a spot far from their barreling buddy MinE — like the other side of the cell. But they can’t stay long. The MinEs follow MinD and MinC and break up the party. In this way, a fluctuating wave of MinCs travels back and forth through the E. coli cell, spending the least amount of time in the cell’s exact center.

The enzymes that kick off cell division are themselves always trying to attach to the membrane, but are usually blocked. They see the distracted MinCs and seize their chance. They collectively pull together and bind to the membrane, splitting the E. coli into two daughter cells that are — voilà! — just the right size.