Figure 2.
Structure of the RyR2 channel pore. (A) Detailed structure of the channel pore of RyR2, illustrating the major structural elements potentially involved in Ca2+ activation. (B) Top view of the channel pore, showing salt bridges potentially formed between D4868, E4872, and R4874. (C) Top view of the channel pore in a closed (left) and open (right) conformation. In the closed state, the constriction point (the narrowest part of the pore) is formed by I4867; when the channel opens, the constriction point shifts to Q4863. (D) Side chain orientation of critical residues in the S6 helices from neighboring subunits. The salt bridge between R4874 and E4872 is disrupted when the channel opens.
