Figure 2.

(a) Ribbon drawing of the human RXRα LBD homodimer (PBD 1MZN). The RXR monomers are colored in black. The N and C termini are labeled “N” and “C”, respectively. Rotation of 180° on the Z-axis of the homodimer results in a geometry equivalent of the starting geometry (i.e., C2 symmetry). The I-boxes are colored in light grey. (b) Ribbon drawing of the hRXRα/hPPARγ LBD heterodimers (PDB 3E00, also see Figure 1). The RXR and PPAR monomers are colored in dark and light grey, respectively.