Figure 3.

Deletion of POTRA domains 1 and 2 has varying effects on BamA diffusion. (A) Histogram showing the measured apparent diffusion coefficients (D_app) for FL-BamA, ΔP1 BamA, and ΔP12 BamA. Median depicted as black line. Data shown on a log10 scale. A KS test indicated a p value of 0.17 between FL-BamA (n = 1759 tracks) and ΔP1 BamA (n = 2206 tracks), and p < 0.0001 between ΔP12 BamA (n = 638 tracks) and both FL-BamA and ΔP1 BamA. (B) Complementary cumulative probability distributions of single-step square displacements for OMP constructs. The black lines represent the best fits to the sum of two exponentials. (C and D) Dependence of the apparent diffusion coefficients on (${\mathrm{D}}_{\text{app}}^{\text{slow}}$) on lag time. The individual apparent diffusion coefficients for the slow (C) and fast (D) modes are shown as a function of inverse lag time. The data points and error bars are derived from the average and SE of the mean values determined from experimental replicates, respectively. The D_true values extracted from the y intercepts are annotated on the figures, and the number in parentheses represents the uncertainty in the least significant digit as given by the SE of the mean from experimental replicates. (C) R² values for each fit are 0.9991, 0.9984, and 0.9710 for FL-BamA-PAmCherry, ΔP1 BamA-PAmCherry, and ΔP12 BamA-PAmCherry, respectively. An extra sum-of-squares F test to compare the y intercepts was performed and yielded a p value of 0.044 for the ${\mathrm{D}}_{\text{true}}^{\text{slow}}$ of FL-BamA and ΔP1 BamA, 0.026 for FL-BamA and ΔP12 BamA, and 0.086 for ΔP1 BamA and ΔP12 BamA. (D) R² values for each fit are 0.9941, 0.9529, and 0.9817 for FL-BamA-PAmcherry, ΔP1 BamA-PAmCherry, and ΔP12 BamA-PAmCherry, respectively. An extra sum-of-squares F test to compare the y intercepts was performed and yielded a p value of 0.20 for the ${\mathrm{D}}_{\text{true}}^{\text{fast}}$ of FL-BamA and ΔP1 BamA, 0.31 for FL-BamA and ΔP12 BamA, and 0.70 for ΔP1 BamA and ΔP12 BamA. To see this figure in color, go online.