Structural overview (A) and the binding pocket (B) of porcine XOR docked with cyadox.

<p>(A) From N to C terminus, iron-sulfur centers domain (purple), FAD domain (dark blue), and molybdopterin (Mo-pt) domain (green) are presented in the 3D structure of porcine XOR model, and the Mo-pt cofactor (yellow), the two iron-sulfur centers (Fe/S I and Fe/S II, red), and the FAD cofactor (bright green) are also included. Cyadox (pink) is docked into the porcine XOR model. (B) Side chains of eight key amino acid residues, Gly47 (blue, in iron-sulfur centers domain), Asn352, Ser360, Arg427, Asp430 and Asp431 (green, in FAD domain), Ser1227 and Lys1230 (yellow, in Mo-pt domain), were screened in a distance of less than 4Å with cyadox by molecular docking. The Mo-pt cofactor (red), the Fe/S I and Fe/S II (grey), the FAD cofactor (purple), cyadox (dark red) and xanthine (blue and grey) are also included.