Extended Data Fig. 1: Characterization of FtsZ WT organization at increasing densities.
From: Chiral and nematic phases of flexible active filaments
a, Schematic illustrating experimental assay and FtsZ treadmilling. FtsZ filaments are recruited to the membrane surface by FtsA. TIRF microscopy allows visualizing filament polymerization dynamics. b, Quantification of the intensity of Alexa488-FtsZ WT during a TIRF titration experiment. The density of FtsZ filaments on the supported membrane is saturated at 3 µM (n = 2 for each FtsZ concentration). c, Snapshots of time lapse movie of a single FtsZ filament treadmilling on a membrane surface. The maximum intensity projection reveals the curved trajectory of the filament. d, Representative fits of mono- and bi-exponential functions to the directional autocorrelation of treadmilling trajectories. Also see Fig. 1c. e, Quantification of the membrane residence time of FtsZ WT by FRAP experiments with increasing bulk concentrations (n = 9, 4, 6, 6, 14, 6, 13 and 7 for [FtsZ] = 0.625, 0.9, 1.15, 1.25, 1.5, 2, 3 and 5 µM). The boxes in e indicate the 25–75th percentiles, whiskers show the maximum/minimum values within the standard deviation and the midline indicates the median. f, Quantification of the FtsZ velocity at increasing concentrations by differential imaging and speckle tracking. (N = 3 independent experiments for each concentration, n = 658, 977, 1412, 1400, 1061, 170 and 126 trajectories were analysed for [FtsZ] = 0.625, 0.9, 1.25, 1.5, 2, 3 and 5 µM). The dot in f indicates the mean and the thick black line the 25–75th percentiles. g, Number of FtsZ treadmilling trajectories within a 100 µm2 area after differential imaging. Dots represent the mean track number of independent experiments; the line indicates the mean of all experiments and the shaded area represents the SEM.
