In situ architecture of a nucleoid- associated biomolecular co- condensate that regulates bacterial cell division

• 成果类型: Article
• 署名作者: Xu, Peng; Schumacher, Dominik; Liu, Chuan; Harms, Andrea; Dickmanns, Marcel; Beck, Florian; Plitzko, Juergen M.; Baumeister, Wolfgang; Sogaard-Andersen, Lotte
• 署名单位: Max Planck Society; Max Planck Society; Max Planck Society
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-9588
• DOI: 10.1073/pnas.2419610121
• 发表日期: 2024-01-07
• 关键词: phase-separation; protein; ORGANIZATION; microtubules

摘要

In most bacteria, cell division depends on the tubulin- homolog FtsZ that polymerizes in a GTP- dependent manner to form the cytokinetic Z- ring at the future division site. Subsequently, the Z- ring recruits, directly or indirectly, all other proteins of the divisome complex that executes cytokinesis. A critical step in this process is the precise positioning of the Z- ring at the future division site. While the divisome proteins are generally conserved, the regulatory systems that position the Z- ring are more diverse. However, these systems have in common that they modulate FtsZ polymerization. In Myxococcus, PomX, PomY, and PomZ form precisely one MDa- sized, nonstoichiometric, nucleoid- associated assembly that spatiotemporally guides Z- ring formation. Here, using cryo- correlative light and electron microscopy together with in situ cryoelectron tomography, we determine the PomXYZ assembly's architecture at close- to- live conditions. PomX forms a porous meshwork of randomly intertwined filaments. Templated by this meshwork, the phase- separating PomY protein forms a biomolecular condensate that compacts and bends the PomX filaments, resulting in the formation of a selective PomXYZ co- condensate that is associated to the nucleoid by PomZ. These studies reveal a hitherto undescribed supramolecular structure and provide a framework for understanding how a nonstoichiometric co- condensate forms, maintains number control, and nucleates GTP- dependent FtsZ polymerization to precisely regulate cell division.