Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Division of Biological Sciences, University of Missouri, Columbia, Missouri, USA.
J Bacteriol. 2024 Oct 24;206(10):e0022524. doi: 10.1128/jb.00225-24. Epub 2024 Sep 18.
In almost all bacteria, the tubulin-like GTPase FtsZ polymerizes to form a "Z-ring" that marks the site of division. FtsZ recruits other proteins, collectively known as the divisome, that together remodel and constrict the envelope. Constriction is driven by peptidoglycan (PG) cell wall synthesis by the glycosyltransferase FtsW and the transpeptidase FtsI (FtsWI), but these enzymes require activation to function. How recruitment of FtsZ to the division site leads to FtsWI activation and constriction remains largely unknown. Previous work in our laboratory demonstrated that an FtsZ-binding protein, FzlA, is essential for activation of FtsWI in the alphaproteobacterium . Additionally, we found that FzlA binds to a DNA translocase called FtsK, suggesting that it may link constriction activation to chromosome segregation. FzlA is conserved throughout Alphaproteobacteria but has only been examined in detail in . Here, we explored whether FzlA function is conserved in diverse Alphaproteobacteria. We assessed FzlA homologs from and , and found that, similar to FzlA, they bind directly to FtsZ and localize to midcell. The FtsZ-FzlA interaction interface is conserved, as we demonstrated that FzlA from each of the three species examined can bind to FtsZ from any of the three . Finally, we determined that FzlA can fulfill the essential function of FzlA when produced in , indicating conservation of function. These results suggest that FzlA serves as an important regulator that coordinates chromosome segregation with envelope constriction across diverse Alphaproteobacteria.IMPORTANCECell division is essential for bacterial replication and must be highly regulated to ensure robust remodeling of the cell wall in coordination with segregation of the genome to daughter cells. In , FzlA plays a major role in regulating this process by activating cell wall synthesis in a manner that couples constriction to chromosome segregation. FzlA is broadly conserved in Alphaproteobacteria, suggesting that it plays a similar function across this class of bacteria. Here, we have shown that, indeed, FzlA biochemical interactions and function are conserved in diverse Alphaproteobacteria. Because FzlA is conserved in Alphaproteobacterial human pathogens, understanding this protein and its interactome could present therapeutic benefits by identifying potential antibiotic targets to treat infections.
在几乎所有细菌中,微管样 GTP 酶 FtsZ 聚合成“Z 环”,标记分裂部位。FtsZ 招募其他统称为分裂体的蛋白质,共同重塑和收缩包膜。收缩由糖基转移酶 FtsW 和转肽酶 FtsI(FtsWI)的肽聚糖(PG)细胞壁合成驱动,但这些酶需要激活才能发挥作用。FtsZ 向分裂部位的募集如何导致 FtsWI 激活和收缩仍然很大程度上未知。我们实验室的先前工作表明,FtsZ 结合蛋白 FzlA 对于在 α-变形菌中的 FtsWI 激活是必不可少的。此外,我们发现 FzlA 结合一种称为 FtsK 的 DNA 转位酶,表明它可能将收缩激活与染色体分离联系起来。FzlA 在整个 α-变形菌中都保守,但仅在 中进行了详细研究。在这里,我们探索了 FzlA 功能是否在不同的 α-变形菌中保守。我们评估了 和 的 FzlA 同源物,并发现与 FzlA 相似,它们直接与 FtsZ 结合并定位于中隔。FtsZ-FzlA 相互作用界面是保守的,因为我们证明了从三种被研究的物种中每种都可以与任何三种中的 FtsZ 结合。最后,我们确定在 中产生的 FzlA 可以完成 FzlA 的必需功能,表明功能保守。这些结果表明,FzlA 作为一种重要的调节剂,在不同的 α-变形菌中协调染色体分离与包膜收缩。
重要性细胞分裂是细菌复制所必需的,必须高度调节以确保细胞壁的稳健重塑与基因组到子细胞的分离相协调。在 中,FzlA 通过以与染色体分离偶联的方式激活细胞壁合成来调节这个过程,从而发挥重要作用。FzlA 在 α-变形菌中广泛保守,表明它在这个细菌类群中发挥类似的功能。在这里,我们已经表明,FzlA 的生化相互作用和功能在不同的 α-变形菌中是保守的。由于 FzlA 在 α-变形菌的人类病原体中保守,因此了解这种蛋白质及其相互作用组可能通过鉴定治疗感染的潜在抗生素靶标而带来治疗益处。