1bhs

HUMAN ESTROGENIC 17BETA-HYDROXYSTEROID DEHYDROGENASEHUMAN ESTROGENIC 17BETA-HYDROXYSTEROID DEHYDROGENASE

Structural highlights 1bhs is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Activity: 17-beta-estradiol 17-dehydrogenase, with EC number 1.1.1.62 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [DHB1_HUMAN] Favors the reduction of estrogens and androgens. Also has 20-alpha-HSD activity. Uses preferentially NADH. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed BACKGROUND: The principal human estrogen, 17 beta-estradiol, is a potent stimulator of certain endocrine-dependent forms of breast cancer. Because human estrogenic 17 beta-hydroxysteroid dehydrogenase (type I 17 beta-HSD) catalyzes the last step in the biosynthesis of 17 beta-estradiol from the less potent estrogen, estrone, it is an attractive target for the design of inhibitors of estrogen production and tumor growth. This human enzyme shares less than 15% sequence identity with a bacterial 3 alpha,20 beta-HSD, for which the three-dimensional structure is known. The amino acid sequence of 17 beta-HSD also differs from that of bacterial 3 alpha,20 beta-HSD by two insertions (of 11 and 14 residues) and 52 additional residues at the C terminus. RESULTS: The 2.20 A resolution structure of type I 17 beta-HSD, the first mammalian steroidogenic enzyme studied by X-ray crystallographic techniques, reveals a fold characteristic of the short-chain dehydrogenases. The active site contains a Tyr-X-X-X-Lys sequence (where X is any amino acid) and a serine residue, features that are conserved in short-chain steroid dehydrogenases. The structure also contains three alpha-helices and a helix-turn-helix motif, not observed in short-chain dehydrogenase structures reported previously. No cofactor density could be located. CONCLUSIONS: The helices present in 17 beta-HSD that were not in the two previous short-chain dehydrogenase structures are located at one end of the substrate-binding cleft away from the catalytic triad. These helices restrict access to the active site and appear to influence substrate specificity. Modeling the position of estradiol in the active site suggests that a histidine side chain may play a critical role in substrate recognition. One or more of these helices may also be involved in the reported association of the enzyme with membranes. A model for steroid and cofactor binding as well as for the estrone to estradiol transition state is proposed. The structure of the active site provides a rational basis for designing more specific inhibitors of this breast cancer associated enzyme. Structure of human estrogenic 17 beta-hydroxysteroid dehydrogenase at 2.20 A resolution.,Ghosh D, Pletnev VZ, Zhu DW, Wawrzak Z, Duax WL, Pangborn W, Labrie F, Lin SX Structure. 1995 May 15;3(5):503-13. PMID:7663947 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Hydroxysteroid dehydrogenase 3D structures

spinqualitylabelsall models 1bhs, resolution 2.20Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image