Figure 2.

Diffusion and dwelling behavior of PolC-PAmCherry in live B. subtilis cells. (a) 3D superresolution reconstruction image of PolC-PAmCherry in untreated B. subtilis, overlaid on a phase contrast image of the cells. The position of each localization is indicated by a single dot with width corresponding to the average localization precision in the lateral plane (25 nm). The axial (z) position is color-coded according to the color bar above. (Red arrows) Regions of PolC enrichment in the cell. (Inset) A representative, color-coded 3D single-molecule trajectory illustrates a PolC-PAmCherry molecule making a transition from diffusing (bottom) to dwelling (top). (b) Distribution of PolC-PAmCherry diffusion coefficients, D, in untreated cells. (Inset) Zoom-in on the 0–0.1 μm²/s region of the original histogram. (Red dashed line) Average apparent diffusion coefficient (0.003 μm²/s) for stationary PolC-PAmCherry molecules measured in fixed cells. (c) Localization probabilities of dwelling events along the longitudinal cellular axis in untreated cells. L: cell length, N: total number of dwelling events analyzed. (d) 3D superresolution reconstruction image of PolC-PAmCherry in HPUra-treated cells. (e) Distribution of PolC-PAmCherry diffusion coefficients, D, in HPUra-treated cells. (f) Localization probabilities of dwelling events in HPUra-treated cells. Scale bars = 1 μm. To see this figure in color, go online.