FtsZ from divergent foreign bacteria can function for cell division in Escherichia coli

Area of Science:

• Microbiology
• Molecular Biology
• Cell Biology

Background:

• FtsZ proteins are essential for bacterial cell division, forming the Z-ring scaffold.
• Divergence in FtsZ amino acid sequences between species can impact function.
• Understanding FtsZ function across species can reveal conserved and divergent mechanisms of cell division.

Purpose of the Study:

• To investigate if divergent FtsZ proteins from Mycoplasma pulmonis (MpuFtsZ) and Bacillus subtilis (BsFtsZ) can support cell division in Escherichia coli.
• To identify genetic modifications required for heterologous FtsZ function in E. coli.
• To elucidate the mechanism of bacterial cell division involving FtsZ and downstream proteins.

Main Methods:

• Genetic engineering to replace C-terminal tails of MpuFtsZ and BsFtsZ with the E. coli FtsZ C-terminal tail.
• Selection for suppressor mutations in E. coli facilitating division by foreign FtsZs.
• Analysis of suppressor strain frequency and genetic pathways involved.

Main Results:

• MpuFtsZ and BsFtsZ, with modified C-terminal tails, successfully supported cell division in E. coli.
• Suppressor mutations, arising at high frequency, identified potential negative regulators or structural pathways of FtsZ.
• The C-terminal tail of FtsZ is crucial for interaction with E. coli division proteins FtsA and ZipA.

Conclusions:

• Highly divergent FtsZ proteins can be functionally complemented in E. coli through specific modifications.
• Bacterial cell division involves a two-part mechanism: FtsZ Z-ring assembly and downstream protein-mediated peptidoglycan remodeling.
• The FtsZ C-terminal peptide acts as a critical linker between FtsZ assembly and cell wall synthesis machinery.