Department of Microbiology, Molecular Genetics, and Immunology, University of Kansas Medical Center, Kansas City, KS 66160
Department of Microbiology, Molecular Genetics, and Immunology, University of Kansas Medical Center, Kansas City, KS 66160.
Proc Natl Acad Sci U S A. 2018 Jul 17;115(29):E6855-E6862. doi: 10.1073/pnas.1806450115. Epub 2018 Jul 2.
Cell division requires the assembly of a protein complex called the divisome. The divisome assembles in a hierarchical manner, with FtsA functioning as a hub to connect the Z-ring with the rest of the divisome and FtsN arriving last to activate the machine to synthesize peptidoglycan. FtsEX arrives as the Z-ring forms and acts on FtsA to initiate recruitment of the other divisome components. In the absence of FtsEX, recruitment is blocked; however, a multitude of conditions allow FtsEX to be bypassed. Here, we find that all such FtsEX bypass conditions, as well as the bypass of FtsK, depend upon the interaction of FtsN with FtsA, which promotes the back-recruitment of the late components of the divisome. Furthermore, our results suggest that these bypass conditions enhance the weak interaction of FtsN with FtsA and its periplasmic partners so that the divisome proteins are brought to the Z-ring when the normal hierarchical pathway is disrupted.
细胞分裂需要组装一个称为分裂体的蛋白质复合物。分裂体以分层的方式组装，其中 FtsA 作为一个枢纽，将 Z 环与分裂体的其余部分连接起来，而 FtsN 最后到达以激活机器合成肽聚糖。当 Z 环形成时，FtsEX 到达并作用于 FtsA，启动其他分裂体组件的招募。在没有 FtsEX 的情况下，招募被阻断；然而，许多条件允许绕过 FtsEX。在这里，我们发现所有这些 FtsEX 绕过条件，以及 FtsK 的绕过，都依赖于 FtsN 与 FtsA 的相互作用，这促进了分裂体后期组件的回溯招募。此外，我们的结果表明，这些绕过条件增强了 FtsN 与 FtsA 及其周质伙伴的弱相互作用，从而使分裂体蛋白在正常分层途径被破坏时被带到 Z 环。
