Figure 1. The structure of LRP5. The LRP5 protein has an intracellular domain (white rectangle), a single transmembrane domain (black rectangle), an extracellular domain containing a signal peptide (blue rectangle), four EGF-like domains (green circles) which are separated by four β-propeller domains (black vertical line and horizontal red bars), and three LDLR repeats (white ovals). Each β-propeller domain has six blades (short black bars) and five YWTD motifs (red bars). The Q89R polymorphism is located in the second blade of the first β-propeller domain (arrow).