Modeled structure of rat PXR-LBD in complex with PNU-142721. Residues that line rat PXR ligand binding pocket and are conserved between human PXR and rat PXR are labeled and colored in gray, while residues that differ between human PXR and rat PXR are highlighted in orange (rat PXR) and magenta (human PXR), respectively. PNU-142721 is colored by elements, with green, red, blue, yellow and cyan representing carbon, oxygen, nitrogen sulfur and chlorine atoms, respectively. [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.]