Figure 5

Conservation of ligand-binding residues. From published X-ray crystallographic structures of human VDR, rat VDR, zebrafish VDR, human PXR, human CAR, and mouse CAR (see Methods for references), amino acid residues that interact with ligands ('ligand-binding residues') were identified. At these amino acid residue positions, the sequences of Ciona intestinalis VDR/PXR, AncR1, AncR2, and AncR3 were compared with the corresponding sequence for human PXR, mouse PXR, rat PXR, rabbit PXR, chicken PXR, Xenopus laevis PXRα, Xenopus laevis PXRβ, zebrafish PXR, human CAR, human VDR, and sea lamprey VDR. The ordinate represents the percent identity of Ciona intestinalis VDR/PXR, AncR1, AncR2, and AncR3 for the corresponding sequences of PXRs, VDRs, or CAR at these ligand-binding residue positions.