Fig. 7.

Position in Full-length RyR. a Top view of the position of DBM RyR Repeat34 superposed onto the RyR2 cryo-EM model (PDB ID 5GO9). DBM RyR Repeat34, RyR2 Repeat34, RyR2 HD1, and RyR2 SPRY3 are colored in pink, blue, yellow, and green, respectively. Helix α0′ is highlighted in red. The boundaries of a single subunit are indicated by straight lines. b Side view of the docked DBM RyR Repeat34. c Zoomed-in view of the docked DBM RyR Repeat34 (pink). RyR2 HD1 and Repeat34 domains are colored in yellow and blue, respectively. The region interacting with HD1 is more structurally conserved than the phosphorylation loop. The DBM-specific residues in Repeat34-HD1 interfaces are colored in purple (Repeat34) and green (HD1). d Sequence alignment between DBM RyR and pig RyR2 for the HD1-Repeat34 interface region, with the main residues involved in the contact colored in green and purple, respectively. e Zoomed-in view of the interface between DBM RyR Repeat34 and the neighboring SPRY3 domain. The two loops involved in the potential contact are shown in dash. Identified phosphorylation sites from full-length insect RyR are colored in red