Figure 2
(a) PMFs across the open pore. Data shown for Ba2+ (
), Ca2+ (
), Mg2+ (
), Na+ (
), K+ (
) and Cl− (
) ions. The main PMF basins are labeled as ①, ② and ③. (b) The pore of RyR1, aligned with the pore axis of the panel above. Key residues are highlighted in color, depending on which PMF feature they contribute to; the orange arrow indicates the direction of ion permeation. The semitransparent bar indicates the position of the membrane. Panel (c) shows the number of water molecules in the second hydration shell of each ion type across the pore. The inset shows the pore radius and its standard error, based on the structures of all umbrella windows, calculated using HOLE101. The panels (d) to (i) show a calcium ion interacting with key residues, as labeled in panel (b). Note that 4 copies of each residue are shown, since RyR1 is a tetramer.
