Dimethylsulfoxide Reductase

Abstract

Dimethylsulfoxide reductase is a molybdenum cofactor‐containing enzyme, which catalyzes the two‐electron reduction of dimethylsulfoxide to dimethylsulfide. The enzyme consists of a single polypeptide chain of 780 amino acids and contains no other cofactor besides the molybdenum cofactor. The overall fold of the enzyme is structurally organized into four domains, which are grouped around the cofactor. The molybdenum cofactor consists of two molybdopterin guanine dinucleotides, which are symmetrically ligating the molybdenum with their dithiolene groups. In the oxidized Mo(VI) form of the enzyme, an oxo group and a serine side chain complete the coordination sphere. The oxo group is the catalytically labile oxygen, which is replaced by an aquo or, possibly, a hydroxo ligand in the reduced Mo(IV) state.