Fig. 1.

Interaction of the nuclear hormone receptor dimer retinoic acid receptor (RAR) − retinoid X receptor (RXR) binding to a short strand of DNA (induced by retinoic acid binding). All RXR heterodimers preferentially bind DNA at two sites of a direct repeat (DR) configuration, separated by one to five nucleic acids, called DR1,DR2, DR3, DR4, and DR5. The binding to a DR5 configuration is shown, resembling binding to hormone response elements (HREs). Upon binding to actual HREs, gene transcription can occur. (Reprinted from Bich et al. [31]. With permission)