Fig. 3: Charged residues at position 181 in Orai1 trigger strong pore dilation and hydration.

The scheme depicts pore-lining residues of the Orai1-channel. The particular positions are indicated on the right. Red arrows (top) indicate pore diameter, as the pore radius was calculated in (A). Water molecules along the pore (bottom) indicate that in (B) the level of pore hydration was determined. A The cavity size of the pore as calculated by HOLE is given. The plots use the following color code, V181K (purple), V181R (blue), V181E (red), V181E⁰ (teal), V181A (cyan), V181F (orange) and Orai1 (wt; black). The shaded areas correspond to the statistical error over the three replicas. Simulation data from 350 to 400 ns was used. B Distribution of water oxygen along the z-axis within 10 Å from the center of the pore. The plots are using the same color code as in (A). Simulation data from last 50 ns was used. The shaded areas correspond to the standard deviation over the three replicas. For (A) and (B), the location of the pore-lining residues R83, K87, R91, L95, F99, V102 and E106 are indicated.