FIG. 8.

How high filament-filament interactions may provide MreB helical structures in vivo with bending rigidity. MreB filaments form a helical structure that spans the length of a rod-shaped bacterial cells. Our results in vitro suggest that filaments within the bundle do not slide under shear (bottom panel), which endows the MreB helical structure with a high resistance to bending. If sliding between filaments were allowed (top panel), the MreB helical structure would bend readily and it could not play a direct role in imposing a rigid cylindrical architecture to rod-shaped bacterial cells.