Figure 1. SmFRET Distance Distributions and structures of Ykt6 in the apo and with DPC conditions.

(a) Apo condition: Distribution of SNARE core to longin domain distances from smFRET results for doubly labeled Ykt6 molecules before adding DPC. Fitting results with two Gaussians are plotted in green (Peaks are centred at 0.85R₀ and 1.39R₀, respectively). (b) DPC condition: Distributions of distance from smFRET results for double labeled Ykt6 molecules in the presence of DPC environment (Ykt6:DPC = 1:10). The Gaussian fitting lines also are included in red line (Peaks are centre at 0.82R₀ and 1.09R₀, respectively). (c) Two structures predicted by our MD simulations showing the structures of doubly labeled Ykt6 in open (left) and closed (right) states. Both structures were simulated based on PDB structure 3KYQ, which was closer to the closed form. Structures of dyes were simulated with assumed structures of Alexa 555 (green) and Alexa 647 (red).