Figure 2.

Sequence alignment of AhRR, AhR, and ARNT. A, sequence alignment of human AhRR and AhR. Secondary structure elements of AhRR are indicated above the alignment. Conserved residues are highlighted in red. AhRR residues interacting with ARNT in the AhRR–ARNT structure (this study) are indicated by blue asterisks (with bHLH-PAS-A) and green asterisks (with PAS-B). AhR residues interacting with ARNT and XRE in the AhR–ARNT–XRE structure (PDB code 5NJ8) (31) are indicated by yellow and black asterisks, respectively. Residues missing in the structural models are surrounded by gray boxes. B, sequence alignment of bovine, human, and mouse ARNT. Secondary structure elements of bovine ARNT are indicated above the alignment. Conserved residues are highlighted in red. ARNT residues interacting with AhRR (this study), AhR (in the AhR–ARNT–XRE structure, PDB code 5NJ8) (31), and HIF-2α (in the HIF-2α–ARNT structure, PDB code 4ZP4) (29) are indicated by blue, yellow, and red asterisks, respectively. The bovine ARNT residues deleted for crystallization in this study are indicated by dashed lines (i)–(iv). Residues missing in the structural models are surrounded by gray boxes.