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

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.

A journey with type IX secretion system effectors: selection, transport, processing and activities

“…First, the extreme C-terminal region of GldJ (8–13 aa) was dispensable for secretion via the T9SS but was required for SprB dynamics [ 24 ], suggesting a link between GldJ and the gliding apparatus. Indeed, GldJ is required for and present in filamentous structures underneath the OM that could serve as rails to guide a moving tread [ 102 ].…”

The prevalence of motility within the human oral microbiota

“…GldJ forms helical tracks on the cell surface that acts as the rack in the rack and pinion assembly that drives gliding motility (41,45). When comparing the phylogenetic tree of the T9SS gliding protein GldJ to other core T9SS proteins, a loss of genera is observed (Figure 7D).…”