Filamentous structures in the cell envelope are associated with the Bacteroidetes gliding machinery

Professor Emeritus Koji Nakayama of the Department of Microbiology and Oral Infection, Nagasaki University Graduate School of Biomedical Sciences, and Dr. Satoshi Shibata (currently a lecturer at the Department of Microbiology and Immunology, Tottori University Faculty of Medicine), in collaboration with researchers at Osaka University, Osaka Metropolitan University, the University of Electro-Communications, and University of Wisconsin-Milwaukee, Milwaukee, USA, have discovered the multirail structure underneath the outer membrane by electron microscopic observation and analysis, regarding the unique gliding motility of Bacteroidetes.
The results of this research were published in Communications Biology on January 23, 2023.

■Abstract
Many bacteria belonging to the phylum Bacteroidetes move on solid surfaces, called gliding motility. In our previous study with the Bacteroidetes gliding bacterium Flavobacterium johnsoniae, we proposed a helical loop track model, where adhesive SprB filaments are propelled along a helical loop on the cell surface. In this study, we observed the gliding cell rotating counterclockwise about its axis when viewed from the rear to the advancing direction of the cell and revealed that one labeled SprB focus sometimes overtook and passed another SprB focus that was moving in the same direction. Several electron microscopic analyses revealed the presence of a possible multi-rail structure underneath the outer membrane, which was associated with SprB filaments and contained GldJ protein. These results provide insights into the mechanism of Bacteroidetes gliding motility, in which the SprB filaments are propelled along tracks that may form a multi-rail system underneath the outer membrane. The insights may give clues as to how the SprB filaments get their driving force.

■Journal information
Title: Filamentous structures in the cell envelope are associated with the Bacteroidetes gliding machinery.
Author: Satoshi Shibata*, Yuhei O. Tahara, Eisaku Katayama, Akihiro Kawamoto, Takayuki Kato, Yongtao Zhu, Daisuke Nakane, Keiichi Namba, Makoto Miyata, Mark J. McBride, and Koji Nakayama*（*Responsible Author）
Journal: Communications Biology
URL: https://www.nature.com/articles/s42003-023-04472-3
DOI: 10.1038/s42003-023-04472-3


This release is also available in Japanese.

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