Hydroxyquinol 1,2‐Dioxygenase

Abstract

Hydroxyquinol 1,2‐dioxygenase (1,2‐HQD) is an intradiol dioxygenase that uses a nonheme ferric iron to activate the substrate for an electrophilic attack by molecular oxygen to cleave hydroxyquinol (1,2,4‐trihydroxybenzene) or chlorohydroxyquinols between the vicinal hydroxyls. This enzyme is involved in the aerobic metabolism of chloroaromatic compounds containing two or more chlorine substituents. The article focuses on the structure–function relationship of 1,2‐HQD and the comparison, at the molecular level, of the structural factors responsible for the differential substrate selectivity in known ring‐cleaving intradiol dioxygenases.