Advances in understanding E. coli cell fission

Abstract

Much of what we know about cytokinesis in bacteria has come from studies with Escherichia coli, and efforts to comprehensively understand this fundamental process in this organism continue to intensify. Major recent advances include in vitro assembly of a membrane-tethered version of FtsZ into contractile rings in lipid tubules, in vitro dynamic patterning of the Min proteins and a deeper understanding of how they direct assembly of the FtsZ-ring to midcell, the elucidation of structures, biochemical activities and interactions of other key components of the cell fission machinery, and the uncovering of additional components of this machinery with often redundant but important roles in invagination of the three cell envelope layers.

Figure 1

Schematic representation of septal ring assembly in E.coli. Indicated are three stages in development of the septal ring, known protein components, and the approximate step at which they become associated with the apparatus. Proteins that are essential for viability are underlined. Proteins assembling at the cytoplasmic face of the inner membrane are in blue, trans-membrane inner-membrane proteins are in black, periplasmic proteins in orange, and outer-membrane (lipo-) proteins are in purple. Regulators of Z-ring positioning are in red. Some septal ring components (listed in box) were left out of the recruitment pathway for clarity, or because pertinent information is missing.