POLAR LOCALIZATION OF THE MIND PROTEIN OF BACILLUS-SUBTILIS AND ITS ROLE IN SELECTION OF THE MID-CELL DIVISION SITE

Cell division in rod-shaped bacteria is initiated by formation of a ri ng of the tubulin-like protein FtsZ at mid-cell. Division site selecti on is controlled by a conserved division inhibitor MinCD, which preven ts aberrant division at the cell poles. The Bacillus subtilis DivIVA p rotein controls the topological specificity of MinCD action. Here we s how that DivIVA is targeted to division sites late in their assembly, after some MinCD-sensitive step requiring FtsZ and other division prot eins has been passed. DivIVA then recruits MinD to the division sites preventing another division from taking place near the newly formed ce ll poles. Sequestration of MinD to the poles also releases the next mi d-cell sites for division. Remarkably, this mechanism of DivIVA action is completely different from that of the equivalent protein MinE of E scherichia coli, even though both systems operate via the same divisio n inhibitor MinCD.