MOLECULAR-CLONING AND AMINO-ACID-SEQUENCE OF THE PORCINE 17-BETA-ESTRADIOL DEHYDROGENASE

We describe the cloning and sequencing of porcine 17 beta-estradiol de hydrogenase. The enzyme performs oxidation 360-fold more efficiently t han reduction, both measured under optimal conditions. It is localized in specialized vesicles of epithelial cells. The cDNA clones were iso lated from a lambda UNI ZAP XR library of porcine kidney and polymeras e-chain-reaction-amplified from templates of uterus epithelium. In bot h tissues, the same enzyme is coded by a transcript of 2.9 kb. It cont ains a 69-b 5'-noncoding region, an open reading frame of 2211 b and a 3'-noncoding region of 624 b. The open reading frame of 737 amino aci ds with a predicted molecular mass 79973Da was confirmed by amino acid sequencing of peptides. The 80-kDa translation product is processed t o the N-terminal 32-kDa enzyme, part of which is then covalently linke d to actin. The estradiol dehydrogenase/actin complex and the 80-kDa t ranslation product comigrate in SDS/PAGE.