3dhe: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
[[Image:3dhe.gif|left|200px]] | [[Image:3dhe.gif|left|200px]] | ||
<!-- | |||
The line below this paragraph, containing "STRUCTURE_3dhe", creates the "Structure Box" on the page. | |||
You may change the PDB parameter (which sets the PDB file loaded into the applet) | |||
or the SCENE parameter (which sets the initial scene displayed when the page is loaded), | |||
or leave the SCENE parameter empty for the default display. | |||
| | --> | ||
| | {{STRUCTURE_3dhe| PDB=3dhe | SCENE= }} | ||
}} | |||
'''ESTROGENIC 17-BETA HYDROXYSTEROID DEHYDROGENASE COMPLEXED DEHYDROEPIANDROSTERONE''' | '''ESTROGENIC 17-BETA HYDROXYSTEROID DEHYDROGENASE COMPLEXED DEHYDROEPIANDROSTERONE''' | ||
| Line 30: | Line 27: | ||
[[Category: Han, Q.]] | [[Category: Han, Q.]] | ||
[[Category: Lin, S X.]] | [[Category: Lin, S X.]] | ||
[[Category: | [[Category: Androgen]] | ||
[[Category: | [[Category: Dehydroepiandrosterone]] | ||
[[Category: | [[Category: Dhea]] | ||
[[Category: | [[Category: Oxidoreductase]] | ||
[[Category: | [[Category: Short-chain dehydrogenase]] | ||
[[Category: | [[Category: Steroid]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May 4 22:00:06 2008'' | |||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | |||
Revision as of 22:00, 4 May 2008
ESTROGENIC 17-BETA HYDROXYSTEROID DEHYDROGENASE COMPLEXED DEHYDROEPIANDROSTERONE
OverviewOverview
Steroid hormones share a very similar structure, but they behave distinctly. We present structures of human estrogenic 17beta-hydroxysteroid dehydrogenase (17beta-HSD1) complexes with dehydroepiandrosterone (DHEA) and dihydrotestosterone (DHT), providing the first pictures to date of DHEA and DHT bound to a protein. Comparisons of these structures with that of the enzyme complexed with the most potent estrogen, estradiol, revealed the structural basis and general model for sex hormone recognition and discrimination. Although the binding cavity is almost entirely composed of hydrophobic residues that can make only nonspecific interactions, the arrangement of residues is highly complementary to that of the estrogenic substrate. Relatively small changes in the shape of the steroid hormone can significantly affect the binding affinity and specificity. The K(m) of estrone is more than 1000-fold lower than that of DHEA and the K(m) of estradiol is about 10 times lower than that of DHT. The structures suggest that Leu-149 is the primary contributor to the discrimination of C-19 steroids and estrogens by 17beta-HSD1. The critical role of Leu-149 has been well confirmed by site-directed mutagenesis experiments, as the Leu-149 --> Val variant showed a significantly decreased K(m) for C-19 steroids while losing discrimination between estrogens and C-19 steroids. The electron density of DHEA also revealed a distortion of its 17-ketone toward a beta-oriented form, which approaches the transition-state conformation for DHEA reduction.
About this StructureAbout this Structure
3DHE is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
ReferenceReference
Dehydroepiandrosterone and dihydrotestosterone recognition by human estrogenic 17beta-hydroxysteroid dehydrogenase. C-18/c-19 steroid discrimination and enzyme-induced strain., Han Q, Campbell RL, Gangloff A, Huang YW, Lin SX, J Biol Chem. 2000 Jan 14;275(2):1105-11. PMID:10625652 Page seeded by OCA on Sun May 4 22:00:06 2008