Structural/functional homology between the bacterial and eukaryotic cytoskeletons.

Structural proteins are now known to be as necessary for controlling cell division and cell shape in prokaryotes as they are in eukaryotes. Bacterial ParM and MreB not only have atomic structures that resemble eukaryotic actin and form similar filaments, but they are also equivalent in function: the assembly of ParM drives intracellular motility and MreB maintains the shape of the cell. FtsZ resembles tubulin in structure and in its dynamic assembly, and is similarly controlled by accessory proteins. Bacterial MinD and eukaryotic dynamin appear to have similar functions in membrane control. In dividing eukaryotic organelles of bacterial origin, bacterial and eukaryotic proteins work together.