Figure 5.

POTRA deletion increases Sec diffusion. (A) Histogram showing the measured apparent diffusion coefficients (D_app) for SecE/FL-BamA, SecE/ΔP1-BamA and SecE/ΔP12-BamA. Median depicted as black line. Data shown on a log₁₀ scale. KS tests indicated a p value of 0.042 between SecE/FL-BamA (n = 494 tracks) and SecE/ΔP1-BamA (n = 493 tracks), a p value of 0.0035 between SecE/FL-BamA and SecE/ΔP12-BamA (n = 591 tracks), and a p value of 0.24 between SecE/ΔP1-BamA and SecE/ΔP12-BamA. (B) Complementary cumulative probability distributions of single-step square displacements for Sec 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 0.9737, 0.9863, and 0.9875 for SecE/FL-BamA, SecE/ΔP1-BamA, and SecE/ΔP12-BamA, respectively. An extra sum-of-squares F test to compare the y intercepts was performed and yielded p values of 0.49 for the ${\mathrm{D}}_{\text{true}}^{\text{slow}}$ of SecE/FL-BamA and SecE/ΔP1-BamA, 0.52 for SecE/FL-BamA and SecE/ΔP12-BamA, and 0.93 for SecE/ΔP1-BamA and SecE/ΔP12-BamA. (D) R² values for each fit are 0.9861, 0.9793, and 0.9907 for SecE/FL-BamA, SecE/ΔP1-BamA, and SecE/ΔP12-BamA, respectively. An extra sum-of-squares F test to compare the y intercepts was performed and yielded a p value of 0.013 for the ${\mathrm{D}}_{\text{true}}^{\text{fast}}$ of SecE/FL-BamA and SecE/ΔP1-BamA, 0.0039 for SecE/FL-BamA and SecE/ΔP12-BamA, and 0.87 for SecE/ΔP1-BamA and SecE/ΔP12-BamA. To see this figure in color, go online.