Cryo-EM structure and polar assembly of the PS2 S-layer of Corynebacterium glutamicum

• 成果类型: Article
• 署名作者: Sogues, Adria; Sleutel, Mike; Petit, Julienne; Megrian, Daniela; Bayan, Nicolas; Wehenkel, Anne Marie; Remaut, Han
• 署名单位: Flanders Institute for Biotechnology (VIB); Vrije Universiteit Brussel; Centre National de la Recherche Scientifique (CNRS); CNRS - National Institute for Biology (INSB); Pasteur Network; Universite Paris Cite; Institut Pasteur Paris; Centre National de la Recherche Scientifique (CNRS); CNRS - National Institute for Biology (INSB); Pasteur Network; Universite Paris Cite; Institut Pasteur Paris; Pasteur Network; Institut Pasteur de Montevideo; Universite Paris Saclay; Centre National de la Recherche Scientifique (CNRS); CEA
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-9404
• DOI: 10.1073/pnas.2426928122
• 发表日期: 2025-08-05
• 关键词: surface-layer; cell-wall; protein; sequence; GROWTH; cspb

摘要

The polar-growing Corynebactertales have a complex cell envelope architecture charac-terized by the presence of a specialized outer membrane composed of mycolic acids. In some Corynebacteriales, this mytomembrane is further supported by proteinaceous surface layer or S-layer, whost function, structure, and mode of assembly remain largely enigmatic. Here, we isolated ex vivo PS2 S-layers from the industrially impor-tant Corynebacterium glutamicuu and determined its atomic structure by 3D cryo-EM reconstruction. PS2 monomers consist of a six-helix bundle core, a three-helix bundle arm, and a C-terminal transmembrane (TM) helix. The PS2 core oligomerizes into hexameric units anchored in the hycomembrane by a channel-like coiled-coil of the TM helices. The PS2 arms mediate trimeric lattice contacts, crystallizing the hexameric units into an intricate semipermeable lattice. Using pulse-chase live cell imaging, we show that the PS2 lattice is incorporated at the poles, coincident with the actinobacterial elon-gasome. Finally, phylogenetic analysis shows a paraphyletic distribution and dispersed chromosomal location of PS2 in Corynebacteriales as a result of multipla recombination events and losses. These findings expand our understanding of S-later biology and enable applications of membrane-supported self-assembling bioengindered materials.