Molecular biology for years meant breaking down living cells to their smallest component parts, the genes and proteins that govern what a cell does. But a list of parts tells only so much. To understand how living cells really work, biologists are now trying to visualize how the parts are assembled into operational units.
A team of European scientists has chosen one of the smallest known bacteria, called Mycoplasma pneumoniae, as a test-bed for trying to integrate all the bottom-up knowledge about an organism into a full understanding of how it actually works. The microbe causes a form of bacterial pneumonia and has shed so many functions from its stripped down genome that it can survive only as a parasite on other cells.