Figure 4
Fluorescence energy transfer (FRET) between YidC and SecYEG in proteoliposomes. Both YidC-Atto520 and SecYEG-Atto647N were reconstituted into proteoliposomes. (a) When both proteins were reconstituted simultaneously and were present in the same proteoliposome FRET was observed, resulting in a decrease of the donor fluorescence (red line) and increase of the acceptor fluorescence when compared with the sum of the fluorescence with the single proteins (black dotted line). (b) No FRET was observed when YidC and SecYEG were reconstituted into separate proteoliposomes and mixed (purple line). (c) As in a, but Atto520 labelled YidC-5S was combined with SecYEG-Atto647N in the same proteoliposomes (green line). The reconstitution of the proteins is shown in Fig. S4.
