2pB_SS4-3Movement of Gliding Motors in Mycoplasma mobile Visualized by High-speed AFM

Mycoplasma mobile, a pathogenic bacterium glides on solid surfaces with a unique mechanism. In the mechanism, "legs" on a cell repeatedly catch and pull sialylated oligosaccharides on host cells. The force for gliding is generated on an internal structure which consists of gliding motors evolved from F-type ATPase/synthase [1]. However, the actual movement of gliding machinery has not been observed. In this study, we focused on visualizing the movement of gliding motors in living cells by high-speed AFM [2]. To prevent Mycoplasma mobile cells from the removal from the glass slide in the observation, they were fixed onto the glass slide by crosslinking with glutaraldehyde [3]. The high-speed AFM visualized particle structures in the cell, which are consistent with the gliding motors reconstructed by electron cryomicroscopy [4, 5]. The particle movements were detected when the moving frequency was reduced by sodium azide, an inhibitor of F-type ATPase/synthase. The individual particles moved about 15 nm reversibly to the left side relative to the gliding direction of cell. [1] Miyata M and Hamaguchi T, Curr. Opin. Microbiol. 29 (2016) 15–21. [2] Ando T, Biophysical Review 9 (2017) 421–429. [3] Yamashita H et al. J. of Mol. Biol. 422 (2012) 300–309. [4] Nishikawa MS and Nakane D et al. Submitted. [5] Nakane D and Miyata M, PNAS 104 (2007) 19518-19523 2pB_SS4-3