Multiple regions along the Escherichia coli FtsK protein are implicated in cell division.

Escherichia coli FtsK is a large 1329 aa integral membrane protein, which links cell division and chromosome segregation through the respective activities of its 200 aa amino-terminal domain, FtsK(N), and its 500 aa carboxy-terminal domain, FtsK(C). A long 600 aa linker, FtsK(L), connects these two domains. Only FtsK(N) is essential for cell division. However, previous observations suggested that the cytoplasmic part of FtsK also participates in the process of septation. Here, we identify two distinct regions within FtsK(L), FtsK(179-331) and FtsK(332-641), which together with FtsK(N), are required for normal septation. We discuss how the implication of multiple regions along the FtsK protein in cell division could participate in the co-ordination of this process with the last stages of chromosome segregation.