Structural and biochemical characterization of human orphan DHRS10 reveals a novel cytosolic enzyme with steroid dehydrogenase activity

Petra Lukacik , Brigitte Keller , Gabor Bunkoczi , Kathryn L Kavanagh , Wen H Lee , Jerzy Adamski , Udo Oppermann (1)

1 Structural Genomics Consortium

To this day, a significant proportion of the human genome remains devoid of functional characterisation. In this work we present evidence that the previously functionally un-characterised product of the human DHRS10 gene is endowed with 17{beta}-hydroxysteroid dehydrogenase activity. 17{beta}-hydroxysteroid dehydrogenase enzymes (17{beta}-HSDs) are primarily involved in the metabolism of steroids at the C-17 position and also of other substrates such as fatty acids, prostaglandins and xenobiotics. In vitro DHRS10 converts NAD +} to NADH in the presence of estradiol, testosterone and 5-androstene-3{beta}, 17{beta}-diol. Furthermore, the product of estradiol oxidation, estrone, was identified in intact cells transfected with a construct plasmid encoding the DHRS10 protein. In-situ fluorescence hybridisation studies have revealed the cytoplasmic localisation of DHRS10. Along with tissue expression data this suggests a role for DHRS10 in the local inactivation of steroids in the CNS and placenta. The crystal structure of the DHRS10 apoenzyme exhibits secondary structure of the short chain dehydrogenase/reductase (SDR) family: a Rossmann-fold with variable loops surrounding the active site. It also reveals a broad and deep active site cleft into which NAD +} and estradiol can be docked in a catalytically competent orientation.

Mots clés: Life Sciences

Petra Lukacik, Brigitte Keller, Gabor Bunkoczi, Kathryn L Kavanagh, Wen H Lee, et al.. Structural and biochemical characterization of human orphan DHRS10 reveals a novel cytosolic enzyme with steroid dehydrogenase activity. Biochemical Journal, 2006, 402 (3), pp.419-427. ⟨10.1042/BJ20061319⟩. ⟨hal-00478654⟩