Structural and functional features of dimeric dihydrodiol dehydrogenase.

Dimeric dihydrodiol dehydrogenase (DD) catalyzes the NADP(+)-dependent oxidation of trans-dihydrodiols of aromatic hydrocarbons to their corresponding catechols. The tertiary structure of dimeric DD consists of a classical dinucleotide binding domain comprising two betaalphabetaalphabeta motifs at the N-terminus, and an eight-stranded, predominantly anti-parallel beta-sheet, forming the C-terminal domain The aim of this review is to summarize the biochemical and structural properties of dimeric DD, compare it to enzymes that are structurally similar, and provide an insight into its catalytic mechanism and membership amongst a unique family of monomeric/oligomeric proteins that most likely share a common ancestry.