FtsZ-mediated spatial-temporal control over septal cell wall synthesis

Area of Science:

• Bacterial cell division
• Microbiology
• Biophysics

Background:

• FtsZ is a tubulin-like GTPase crucial for bacterial cytokinesis.
• It organizes the divisome, the complex responsible for synthesizing new cell wall.
• FtsZ's precise role in spatial-temporally organizing the divisome for robust cell wall constriction remains unclear.

Purpose of the Study:

• To elucidate the spatial-temporal organization mechanism of the bacterial divisome by FtsZ during cell wall constriction.
• To understand how FtsZ regulates septal peptidoglycan synthesis and cell division in Escherichia coli.

Main Methods:

• Theoretical modeling
• Experimental validation in Escherichia coli

Main Results:

• FtsZ treadmilling Brownian ratcheting acts as a template for FtsWIQLB-FtsN complex formation and homogenizes septal peptidoglycan synthesis at the early division stage.
• FtsN density increases by binding to denuded peptidoglycan, activating FtsWIQLB for synthesis and making FtsZ dispensable at later stages.
• This mechanism ensures robust and even cell wall constriction during bacterial cytokinesis.

Conclusions:

• FtsZ plays a dual role in bacterial cell division, acting as an initial organizer and later becoming dispensable.
• The study proposes a framework for FtsZ-mediated spatial-temporal regulation of septal cell wall constriction.
• Variations in this mechanism may exist across different bacterial species.