The cell division protein FzlA performs a conserved function in diverse alphaproteobacteria

Area of Science:

• Bacteriology
• Cell Biology
• Microbial Genetics

Background:

• Bacterial cell division relies on the FtsZ-ring and divisome complex.
• Peptidoglycan synthesis enzymes (FtsWI) must be activated for cell constriction.
• FzlA protein in *Caulobacter crescentus* activates FtsWI and links constriction to chromosome segregation.

Purpose of the Study:

• To investigate the conserved function of FzlA in diverse Alphaproteobacteria.
• To determine if FzlA homologs from *Rickettsia parkeri* and *Agrobacterium tumefaciens* interact with FtsZ and localize correctly.
• To assess if *A. tumefaciens* FzlA can functionally replace *C. crescentus* FzlA.

Main Methods:

• Sequence analysis of FzlA homologs.
• In vitro binding assays between FtsZ and FzlA from different species.
• Localization studies of FzlA homologs in *C. crescentus*.
• Functional complementation assays by expressing *A. tumefaciens* FzlA in *C. crescentus*.

Main Results:

• FzlA homologs from *R. parkeri* and *A. tumefaciens* bind FtsZ and localize to the midcell.
• The interaction interface between FtsZ and FzlA is conserved across the studied species.
• *A. tumefaciens* FzlA can rescue the essential function of FzlA in *C. crescentus*.

Conclusions:

• FzlA is a conserved regulator that coordinates chromosome segregation and cell envelope constriction in Alphaproteobacteria.
• The conserved function of FzlA suggests its potential as a therapeutic target in Alphaproteobacterial infections.