Solving the riddle of the intradiol and extradiol catechol dioxygenases: how do enzymes control hydroperoxide rearrangements?

Metallo-enzymes catalyse a rich variety of biochemical reactions, some of which have little or no precedent in laboratory chemistry. Studies of such enzyme-catalysed reactions have benefited greatly in recent years from the pace of new protein X-ray crystallographic structures, but a detailed understanding of enzyme-catalysed reactions at the molecular level has required an interplay between structural studies, mechanistic studies, and small molecule model studies. This article will describe recent studies on an intriguing and long-standing puzzle in mechanistic enzymology, that of the non-haem iron-dependent catechol dioxygenases.