Figure 7.

Model for SlmA-mediated NO. Schematic representation of SlmA-mediated NO. OriC sites, opposite the Ter region, are shown as red circles. FtsZ molecules are green arrows with yellow outline. Left: Without functional SlmA, FtsZ polymerizes to form a premature Z-ring, and in the presence of cellular stress caused by the inhibition of chromosome partition, DNA replication or a non-functional Min system, this leads to nucleoid guillotining and DNA fragmentation. Right: In the presence of SlmA (blue), the Z-ring cannot form over the DNA until replication of the Ter MD because SlmA does not bind the Ter MD. Cell division is thus coordinated with DNA segregation as the cell division machinery assembles right before the commencement of DNA segregation. Close up of the SlmA–FtsZ interaction, illustrating that SlmA disrupts Z-ring formation by inserting between FtsZ molecules and ultimately perturbing FtsZ higher order polymerization.