Figure 8: Tridimensional structure of the catalytic homodimer of hydroxyquinol 1,2-dioxygenase from N. simplex as determined by X-ray crystallography (PDB code: 1TMX). (a) Global structure of the homodimer showing the tight packing between subunits; (b) close look to the iron center, coordinating amino acids, and substrate binding site close to the iron atom. The structure of hydroxyquinol 1,2-dioxygenase was solved in the presence of benzoate, a competitive inhibitor which binds to the substrate binding site.