Examination of the interaction between FtsZ and MinCN in E. coli suggests how MinC disrupts Z rings

Area of Science:

• Bacterial cell division
• Molecular mechanisms of cell cycle regulation
• Protein-protein interactions in prokaryotes

Background:

• The Min system in Escherichia coli regulates cell division by preventing Z-ring assembly at cell poles.
• The division inhibitor MinC targets FtsZ, a key protein in Z-ring formation.
• MinC has two domains; the C-terminal domain (MinC(C)) was previously shown to interfere with FtsZ interactions.

Purpose of the Study:

• To investigate the interaction between the N-terminal domain of MinC (MinC(N)) and FtsZ.
• To identify key regions of FtsZ involved in the MinC(N)-FtsZ interaction.

Main Methods:

• Screening for FtsZ mutations resistant to MinC(N) activity.
• In vivo and in vitro assays using wild-type and mutant FtsZ (FtsZ-N280D).
• Analysis of FtsZ-MinC interaction strength.

Main Results:

• An alpha-helix at the FtsZ subunit interface is critical for MinC(N) activity.
• The FtsZ-N280D mutant showed reduced interaction with MinC and resistance to MinC(N).
• MinC disrupts both FtsZ-FtsA/ZipA and FtsZ-FtsZ interactions.

Conclusions:

• MinC(N) targets a specific alpha-helix in FtsZ, disrupting FtsZ-FtsZ interactions.
• MinC inhibits cell division by interfering with essential FtsZ polymerization and FtsA/ZipA binding.
• An updated model proposes MinC disrupts two critical FtsZ interactions for Z-ring formation.