SDR Structure, Mechanism of Action, and Substrate Recognition

Short chain dehydrogenases/reductases (SDR) constitute a large protein family. The SDR family now includes more than 1,000 enzymes from humans, mammals, insects and bacteria, and exhibits a wide variety of substrate specificity for steroids, retinoids, prostaglandins, sugars, alcohols and other small molecules. These enzymes have a residue identity level of 15-30 perent. Much has been done in the last decade to understand the structure function relationships in the SDR enzymes. This review summarizes recent progress of structural and functional studies of the enzymes belonging to the SDR family (X ray crystal structure analyses and site directed mutagenesis studies). Based on these studies, the three dimensional structure, catalytic mechanism, coenzyme specificity, and substrate specificity of the SDR enzymes are discussed.