Choudhury Jagrity, Chaudhuri Barnali N
GN Ramachandran Protein Center, CSIR Institute of Microbial Technology, Chandigarh, India.
Academy of Scientific and Innovative Research (AcSIR), AcSIR Headquarters CSIR-HRDC Campus, Postal Staff College Area, Ghaziabad, India.
Cytoskeleton (Hoboken). 2025 Jul;82(7):432-443. doi: 10.1002/cm.21975. Epub 2024 Dec 19.
Z-ring formation by FtsZ, the master assembler of the divisome, is a key step in bacterial cell division. Membrane anchoring of the Z-ring requires the assistance of dedicated Z-ring binding proteins, such as SepF and FtsA. SepF participates in bundling and membrane anchoring of FtsZ in gram-positive bacteria. We report in vitro biophysical studies of the interactions between FtsZ and a cytoplasmic component of cognate SepF from three different bacteria: Mycobacterium tuberculosis, Staphylococcus aureus, and Enterococcus gallinarum. While the cytosolic domain of SepF from M. tuberculosis is primarily a dimer, those from S. aureus and E. gallinarum polymerize to form ring-like structures. Mycobacterial SepF helps in the bundling of FtsZ filaments to form thick filaments and large spirals. On the other hand, ring-forming SepF from the Firmicutes bundle FtsZ into tubules. Our results suggest that the oligomeric form of SepF directs how it bundles FtsZ filaments.
FtsZ作为分裂体的主要组装蛋白，其形成Z环是细菌细胞分裂的关键步骤。Z环的膜锚定需要特定的Z环结合蛋白（如SepF和FtsA）的协助。SepF参与革兰氏阳性菌中FtsZ的成束和膜锚定过程。我们报告了对来自三种不同细菌（结核分枝杆菌、金黄色葡萄球菌和鸡肠球菌）的FtsZ与同源SepF的细胞质成分之间相互作用的体外生物物理研究。结核分枝杆菌的SepF胞质结构域主要是二聚体，而金黄色葡萄球菌和鸡肠球菌的SepF则聚合成环状结构。分枝杆菌的SepF有助于FtsZ丝束形成粗丝和大螺旋。另一方面，来自厚壁菌门的形成环的SepF将FtsZ聚集成微管。我们的结果表明，SepF的寡聚形式决定了它如何将FtsZ丝束在一起。
