Exploring Gliding Motility: Model of Helical Transport of Cell Surface Proteins in Flavobacterium Johnsoniae
Mei-Hsien Tu1*, Hirofumi Wada2, Hsuan-Yi Chen1
1Department of Physics, National Central University, Jung-Li, Taiwan
2Department of Physics, Ritsumeikan University, Shiga, Japan
* presenting author:MeiHsien Tu, email:isfahan@ncu.edu.tw
Cells of Flavobacterium johnsoniae exhibit rapid gliding on a solid surface powered by the migration of surface adhesive proteins SprB along a left-handed helical loop on cell surfaces. We develop a model of rigidly coupled adhesins on a helical loop to study the mechanism of this gliding motility. The model takes into account the helical geometry of the loop and the stochastic binding/unbinding dynamics of SprB. The numerical calculations reproduce the main features for the movement of Flavobacterium johnsoniae observed in the experiments. Cell body translation along its long axis displays a bidirectional motion via spontaneous symmetry breaking as predicted in a previous simple one-dimensional model. However, this linear movement has a characteristic switching length comparable to cell length due to end effect. As a cell undergoes translation, the cell body rotates counterclockwise about its principle axis when viewed from its rear. Cells with helical loop that makes one full turn from one pole of the cell to the other pole show left-turn trajectories. Furthermore, SprBs with strong binding at a cell pole naturally introduce an asymmetric distribution of the force generation to uplift the cell body and achieve the end-over-end fipping.

Keywords: Gliding