FIGURE 3.
Homo-oligomerization of Wzt expressed in CHO cells in the absence of Wzm. A. Apparent FRET efficiency (Eapp) maps of representative cells expressing Wzt. B. Distributions of FRET efficiencies (Eapp histograms) across the pixels composing the FRET efficiency maps shown in panel A. C. The peak positions of 380 cells showing single or dominant peaks in their corresponding Eapp histograms were binned and used to form meta-histograms (circles), and then fitted simultaneously to five correlated Gaussians shown individually (red, green, cyan, brown, and blue lines) or as a sum (black line). The five peaks in the meta-histogram correspond to different configurations of a rhombus-shaped tetramer shown in panel D. The peak positions of the five simulated Gaussians were determined from a single adjustable parameter, the pair-wise FRET efficiency (Ep) (see equations in panel D). The best fit was obtained for Ep ± S.D. equal to 0.139 ±0.013. D. A rhombus-shaped tetramer model used to interpret the results in panel C. Ep is the pair-wise FRET efficiency between a single donor (D) and a single acceptor (A).