Fig. 7
From: Cryo-EM reveals ligand induced allostery underlying InsP3R channel gating
Schematic of ligand-induced conformational changes underlying activation of InsP3R1. Top view of the channel along the 4-fold axis from the cytosolic side (left panel). Depicted are the LBDs and CTDs for each InsP3R1 protomer coloured by subunit. Section of tetrameric InsP3R1 through its 4-fold axis is viewed parallel to the membrane plane (right panel); regions of constriction and SF are indicted with red circles, Ca2+ ion - yellow sphere. Ligand-evoked domain motions are indicated with arrows. Presumably, conformational changes evoked by binding of AdA between the β-TF2 and ARM1 domains are propagated via several inter-subunit interfaces (β-TF1/β-TF2, CTD/β-TF2 and β-TF1/ARM3) in the cytoplasmic solenoid structure to the ILD/LNK assembly that can exert force directly on the TMDs to open the channel gate
