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

Abstract

SummaryEscherichia 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, FtsKN, and its 500 aa carboxy-terminal domain, FtsKC. A long 600 aa linker, FtsKL, connects these two domains. Only FtsKN 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 FtsKL, FtsK179-331 and FtsK332-641, which together with FtsKN, 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.

In the Beginning, Escherichia coli Assembled the Proto-ring: An Initial Phase of Division

“…FtsK is needed to resolve possible chromosome cointegrates resulting from replication (76,77). FtsEX, an ATP-binding cassette transporter-like complex, acts as a regulator of cell wall hydrolysis at the division site.…”

Site-directed Fluorescence Labeling Reveals a Revised N-terminal Membrane Topology and Functional Periplasmic Residues in the Escherichia coli Cell Division Protein FtsK

“…Several theories have been proposed regarding the mechanism of action for FtsK, all of which rely on alterations to the protein-protein interactions between FtsK and various components of the division machinery, collectively known as the divisome (10,17,23,24). In 2010, Dubarry et al (17) speculated on the functional link between FtsK in cell division and DNA segregation and suggested a mechanism of action that highlights its potential role as a checkpoint of bacterial cell division.…”

“…FtsK N is the only portion of FtsK essential for division (14 -16), although the precise role that FtsK N plays in septation is still unknown. Immediately downstream of FtsK N is a highly flexible linker domain rich in proline and glutamine (FtsK L ), whose length is variable between bacterial species (7,17). This linker region connects FtsK N to the remaining ϳ500 amino acids at the C terminus of FtsK (FtsK C ).…”

Mechanisms and Controls of DNA Replication in Bacteria

“…FtsK also contains a linker, FtsK L , localized between the FtsK N and FtsK C domains (Bigot et al, 2004). Recently two distinct regions within FtsK L; have been identified (FtsK179-331 and FtsK332-641), which together with FtsK N , are required for normal septation in E. coli (Dubarry et al, 2010). FtsK C can lead to the dimerization of circular chromosomes, thereby compromising their segregation ( Figure 5).…”

“…In this process the FtsK protein is very important as it acts by coordinating cell division with chromosome segregation through the activities of its N-transmembranal domain (FtsK N ) and its C-cytosolic domain (FtsK C ), respectively. FtsK N is the target for the division protein that forms the septum FtsZ, which stabilizes the interactions of FtsK with the other components of the divisome FtsQ, FtsI and FtsL (Aussel et al, 2002;Dubarry et al, 2010). FtsK also contains a linker, FtsK L , localized between the FtsK N and FtsK C domains (Bigot et al, 2004).…”