Fig. 1.

Microstructures in the bacterial cell. Structures such as the chemoreceptor array, the FtsZ ring, and the flagellar motor are made of multiple subunits operating in a coordinated fashion. Many of these assembled structures have been observed directly in electron microscopy images (23, 61, 95, 96). The properties of these structures are unique because the mechanics and chemistry in the subunits are coupled. Subunits are also mechanically coupled to each other, leading to cooperative effects.