Figure 4 Three possible binding models between TRPC3 and type-1 IP3 receptor. (a) Top-to-top binding at the center of both channels. The large dimensions of TRPC3 (green) imply a possible top-to-top binding with IP3R1 (brown), although a conformational change is needed for their close contact. The large space between the two membranes enables simultaneous association between TRPC3 and macromolecules including IP3R1 and PLC (Kiselyov et al., 1998; Nishida et al., 2003; van Rossum et al., 2005). (b) Corner binding reduces the space between the membranes. (c) Side-by-side binding results in the narrowest membrane distance.

© International Union of Crystallography 2008