Figure 2.

BamA POTRA domains anchor the BAM complex in the E. coli cell envelope. (A) Histogram showing the measured apparent diffusion coefficients (D_app) for BamA-PAmCherry, OmpLA-PAmCherry, and BamA barrel-PAmCherry. Median depicted as black line. Data shown on a log₁₀ scale. A Kolmogorov-Smirnov (KS) test indicated a p < 0.0001 between BamA (n = 648 tracks) and OmpLA (n = 585 tracks) and between BamA and BamA barrel (n = 1039 tracks), and p = 0.27 between OmpLA and BamA barrel. (B) Complementary cumulative squared displacement distributions for OMP constructs. The black lines represent the best fits to a double exponential mixture model. (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 0.9947, 0.9675, and 0.9937 for BamA-PAmCherry, OmpLA-PAmCherry, and BamA barrel-PAmCherry, respectively. An extra sum-of-squares F test to compare the y intercepts was performed and yielded a p value of 0.39 for BamA and OmpLA, 0.52 for BamA and BamA barrel, and 0.64 for OmpLA and BamA barrel. (D) R² values for each fit are 0.9488, 0.9610, and 0.9583 for BamA-PAmCherry, OmpLA-PAmCherry, and BamA barrel-PAmCherry, respectively. An extra sum-of-squares F test to compare the y intercepts was performed and yielded a p value of 0.0067 for the ${\mathrm{D}}_{\text{true}}^{\text{fast}}$ of BamA and OmpLA, 0.025 for BamA and BamA barrel, and 0.57 for OmpLA and BamA barrel. To see this figure in color, go online.