Noncovalent interactions of DHODH with 46 (cyan, PDB 6CJG) and 43 (yellow, PDB 6CJF). (A) and (B) display hydrophobic interactions and (C) and (D) hydrogen-bonding interactions (dashed lines). 43 shown as modeled in predominant conformation. Nitrogen is shown in blue, oxygen in red, sulfur in yellow, chlorine in green, fluorine in light blue, and hydrogens in white.