Figure 9. Structure of the DNA binding domain of the androgen receptor. A) The protein structure is represented in the one letter code. The domain consists of two zinc cluster modules, which are stabilized by the coordination binding of a zinc atom (red dot) by 4 cysteine residues (yellow). The first zinc cluster contains the P-box (proximal box) of which three residues determine androgen response element recognition. The second zinc cluster contains the D-box (distal box) in which amino acids are located that are involved in protein-protein interactions with a second receptor molecule in the homodimer complex. B) Structure of the AR-DBD bound to DNA (Pdb 1R41). C) Consensus androgen receptor response element.