7SAX

Structure of GldLM, the proton-powered motor that drives Type IX protein secretion and gliding motility in Sphingobacterium wenxiniae

7SAX の概要

• エントリーDOI: 10.2210/pdb7sax/pdb
• EMDBエントリー: 24958
• 分子名称: GldM, GldL (2 entities in total)
• 機能のキーワード: type ix secretion system, motor protein
• 由来する生物種: Sphingobacterium wenxiniae; 詳細
• タンパク質・核酸の鎖数: 7
• 化学式量合計: 172426.82

構造登録者

Hennell James, R.,Deme, J.C.,Lea, S.M. (登録日: 2021-09-23, 公開日: 2022-03-23, 最終更新日: 2024-06-05)

主引用文献

Hennell James, R.,Deme, J.C.,Hunter, A.,Berks, B.C.,Lea, S.M.
Structures of the Type IX Secretion/Gliding Motility Motor from across the Phylum Bacteroidetes.
Mbio, 13:e0026722-e0026722, 2022

PubMed Abstract: Gliding motility using cell surface adhesins, and export of proteins by the type IX secretion system (T9SS) are two phylum-specific features of the Bacteroidetes. Both of these processes are energized by the GldLM motor complex, which transduces the proton motive force at the inner membrane into mechanical work at the outer membrane. We previously used cryo-electron microscopy to solve the structure of the GldLM motor core from Flavobacterium johnsoniae at 3.9-Å resolution (R. Hennell James, J. C. Deme, A. Kjaer, F. Alcock, et al., Nat Microbiol 6:221-233, 2021, https://dx.doi.org/10.1038/s41564-020-00823-6). Here, we present structures of homologous complexes from a range of pathogenic and environmental species at up to 3.0-Å resolution. These structures show that the architecture of the GldLM motor core is conserved across the phylum, although there are species-specific differences at the N terminus of GldL. The resolution improvements reveal a cage-like structure that ties together the membrane-proximal cytoplasmic region of GldL and influences gliding function. These findings add detail to our structural understanding of bacterial ion-driven motors that drive the T9SS and gliding motility. Many bacteria in the phylum use the type IX secretion system to secrete proteins across their outer membrane. Most of these bacteria can also glide across surfaces using adhesin proteins that are propelled across the cell surface. Both secretion and gliding motility are driven by the GldLM protein complex, which forms a nanoscale electrochemical motor. We used cryo-electron microscopy to study the structure of the GldLM protein complex from different species, including the human pathogens Porphyromonas gingivalis and Capnocytophaga canimorsus. The organization of the motor is conserved across species, but we find species-specific structural differences and resolve motor features at higher resolution. This work improves our understanding of the type IX secretion system, which is a virulence determinant in human and animal diseases.

PubMed: 35446127
DOI: 10.1128/mbio.00267-22

実験手法

ELECTRON MICROSCOPY (3 Å)