Location of the luminal water pore of SERCA. (A) Structure of SERCA bound to PLB embedded in a lipid bilayer. The proteins are shown as ribbons, and the phosphate groups of the lipids are shown as gold spheres. For clarity, the TM helices are colored as follows: TM6, blue; TM8, green; TM9, purple; TM10, orange. (B) Luminal water pore of SERCA located between transmembrane helices TM6, TM8, TM9, and TM10; the pore is shown as a yellow surface. To see this figure in color, go online.