Figure 6.

Ligand-bound conformational dynamics of FeuA. Fluorescence trajectories of surface-immobilized FeuA(Q112C/I255C) in the presence of 100 μM FeBB are shown. Time resolution is 4 ms. The top panel shows calculated apparent FRET efficiency (blue) from the donor (green) and acceptor (red) photon counts as presented in the bottom panel. The orange lines indicate the average apparent FRET efficiency value. The cartoon depicts the ligand-bound open and closed states with the estimated lifetimes indicated. The number of analyzed molecules is provided in Table S3. To see this figure in color, go online.