Fig. 1.

Putative Ca²⁺-binding and caffeine-binding sites in RyR1. a The architecture of RyR1 is depicted in ribbon representation, with the shell (residues 1-3666) colored blue, the core solenoid (CSol, residues 3667-4253) green, the transmembrane region and S6c (residues 4540-4956) orange, and the C-terminal domain (CTD, residues 4957-5037) pink. Atomic coordinates (PDB accession code: 5T9V) from des Georges et al.²⁰ were used. b Closed-up view of boxed area in (a). The binding sites of Ca²⁺ c and caffeine d, with proposed interacting residues labeled are depicted in ribbon representation