Fig. 5.

Dynamics of cytoplasmic domains. (A) Overlay of (Left) AtTPC1_WT and (Right) AtTPC1_DA crystal structures colored by B-factor value (100–450 Ų) (see Methods and SI Appendix, Supplementary Discussion). (B) Side views of AtTPC1_WT (red) and AtTPC1_DDE (blue). (C) Views from (Top Left) side and (Top Right) bottom of EF3 for overlaid AtTPC1_DDE (blue) and AtTPC1_WT crystal structures (red, PDB ID code 5DQQ). CTD interactions are omitted for clarity. Ca²⁺-ion binding sites in (Bottom Right) EF1–EF2 and (Bottom Left) EF3–EF4. (D) View of EF3-CTD and EF3-EF4 interactions and connection to VSD2. (E) Structure of the CTD in AtTPC1_DDE and a possible coupling pathway to the pore gate and Ca_a²⁺. Dashed lines indicate the hypothetical Ca_a²⁺ ion position.