1xjb

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(New page: 200px<br /> <applet load="1xjb" size="450" color="white" frame="true" align="right" spinBox="true" caption="1xjb, resolution 1.90&Aring;" /> '''Crystal structure o...)
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'''Crystal structure of human type 3 3alpha-hydroxysteroid dehydrogenase in complex with NADP(H), citrate and acetate molecules'''<br />
'''Crystal structure of human type 3 3alpha-hydroxysteroid dehydrogenase in complex with NADP(H), citrate and acetate molecules'''<br />
==Overview==
==Overview==
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The aldo-keto reductase (AKR) human type 3 3alpha-hydroxysteroid, dehydrogenase (h3alpha-HSD3, AKR1C2) plays a crucial role in the, regulation of the intracellular concentrations of testosterone and, 5alpha-dihydrotestosterone (5alpha-DHT), two steroids directly linked to, the etiology and the progression of many prostate diseases and cancer., This enzyme also binds many structurally different molecules such as, 4-hydroxynonenal, polycyclic aromatic hydrocarbons, and indanone. To, understand the mechanism underlying the plasticity of its, substrate-binding site, we solved the binary complex structure of, h3alpha-HSD3-NADP(H) at 1.9 A resolution. During the refinement process, we found acetate and citrate molecules deeply engulfed in the, steroid-binding cavity. Superimposition of this structure with the, h3alpha-HSD3-NADP(H)-testosterone/acetate ternary complex structure, reveals that one of the mobile loops forming the binding cavity operates a, slight contraction movement against the citrate molecule while the side, chains of many residues undergo numerous conformational changes, probably, to create an optimal binding site for the citrate. These structural, changes, which altogether cause a reduction of the substrate-binding, cavity volume (from 776 A(3) in the presence of testosterone/acetate to, 704 A(3) in the acetate/citrate complex), are reminiscent of the, "induced-fit" mechanism previously proposed for the aldose reductase, another member of the AKR superfamily. We also found that the replacement, of residues Arg(301) and Arg(304), localized near the steroid-binding, cavity, significantly affects the 3alpha-HSD activity of this enzyme, toward 5alpha-DHT and completely abolishes its 17beta-HSD activity on, 4-dione. All these results have thus been used to reevaluate the binding, mode of this enzyme for androgens.
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The aldo-keto reductase (AKR) human type 3 3alpha-hydroxysteroid dehydrogenase (h3alpha-HSD3, AKR1C2) plays a crucial role in the regulation of the intracellular concentrations of testosterone and 5alpha-dihydrotestosterone (5alpha-DHT), two steroids directly linked to the etiology and the progression of many prostate diseases and cancer. This enzyme also binds many structurally different molecules such as 4-hydroxynonenal, polycyclic aromatic hydrocarbons, and indanone. To understand the mechanism underlying the plasticity of its substrate-binding site, we solved the binary complex structure of h3alpha-HSD3-NADP(H) at 1.9 A resolution. During the refinement process, we found acetate and citrate molecules deeply engulfed in the steroid-binding cavity. Superimposition of this structure with the h3alpha-HSD3-NADP(H)-testosterone/acetate ternary complex structure reveals that one of the mobile loops forming the binding cavity operates a slight contraction movement against the citrate molecule while the side chains of many residues undergo numerous conformational changes, probably to create an optimal binding site for the citrate. These structural changes, which altogether cause a reduction of the substrate-binding cavity volume (from 776 A(3) in the presence of testosterone/acetate to 704 A(3) in the acetate/citrate complex), are reminiscent of the "induced-fit" mechanism previously proposed for the aldose reductase, another member of the AKR superfamily. We also found that the replacement of residues Arg(301) and Arg(304), localized near the steroid-binding cavity, significantly affects the 3alpha-HSD activity of this enzyme toward 5alpha-DHT and completely abolishes its 17beta-HSD activity on 4-dione. All these results have thus been used to reevaluate the binding mode of this enzyme for androgens.
==Disease==
==Disease==
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==About this Structure==
==About this Structure==
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1XJB is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with ACT, SO4, NAP, EDO, CIT and BME as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/3-alpha-hydroxysteroid_dehydrogenase_(A-specific) 3-alpha-hydroxysteroid dehydrogenase (A-specific)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.1.213 1.1.1.213] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1XJB OCA].
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1XJB is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=ACT:'>ACT</scene>, <scene name='pdbligand=SO4:'>SO4</scene>, <scene name='pdbligand=NAP:'>NAP</scene>, <scene name='pdbligand=EDO:'>EDO</scene>, <scene name='pdbligand=CIT:'>CIT</scene> and <scene name='pdbligand=BME:'>BME</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/3-alpha-hydroxysteroid_dehydrogenase_(A-specific) 3-alpha-hydroxysteroid dehydrogenase (A-specific)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.1.213 1.1.1.213] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XJB OCA].
==Reference==
==Reference==
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[[Category: Breton, R.]]
[[Category: Breton, R.]]
[[Category: Cantin, L.]]
[[Category: Cantin, L.]]
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[[Category: Cote, P.L.]]
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[[Category: Cote, P L.]]
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[[Category: Couture, J.F.]]
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[[Category: Couture, J F.]]
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[[Category: Jesus-Tran, K.Pereira.de.]]
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[[Category: Jesus-Tran, K Pereira de.]]
[[Category: Labrie, F.]]
[[Category: Labrie, F.]]
[[Category: Legrand, P.]]
[[Category: Legrand, P.]]
[[Category: Luu-The, V.]]
[[Category: Luu-The, V.]]
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[[Category: Roy, A.M.]]
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[[Category: Roy, A M.]]
[[Category: ACT]]
[[Category: ACT]]
[[Category: BME]]
[[Category: BME]]
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[[Category: human 3alphahds3; aldo-keto reductase; nadp; induce-fit mecanism]]
[[Category: human 3alphahds3; aldo-keto reductase; nadp; induce-fit mecanism]]
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''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 12 20:06:13 2007''
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''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:55:21 2008''

Revision as of 13:55, 21 February 2008


1xjb, resolution 1.90Å

Drag the structure with the mouse to rotate

Crystal structure of human type 3 3alpha-hydroxysteroid dehydrogenase in complex with NADP(H), citrate and acetate molecules

Contents

Overview

The aldo-keto reductase (AKR) human type 3 3alpha-hydroxysteroid dehydrogenase (h3alpha-HSD3, AKR1C2) plays a crucial role in the regulation of the intracellular concentrations of testosterone and 5alpha-dihydrotestosterone (5alpha-DHT), two steroids directly linked to the etiology and the progression of many prostate diseases and cancer. This enzyme also binds many structurally different molecules such as 4-hydroxynonenal, polycyclic aromatic hydrocarbons, and indanone. To understand the mechanism underlying the plasticity of its substrate-binding site, we solved the binary complex structure of h3alpha-HSD3-NADP(H) at 1.9 A resolution. During the refinement process, we found acetate and citrate molecules deeply engulfed in the steroid-binding cavity. Superimposition of this structure with the h3alpha-HSD3-NADP(H)-testosterone/acetate ternary complex structure reveals that one of the mobile loops forming the binding cavity operates a slight contraction movement against the citrate molecule while the side chains of many residues undergo numerous conformational changes, probably to create an optimal binding site for the citrate. These structural changes, which altogether cause a reduction of the substrate-binding cavity volume (from 776 A(3) in the presence of testosterone/acetate to 704 A(3) in the acetate/citrate complex), are reminiscent of the "induced-fit" mechanism previously proposed for the aldose reductase, another member of the AKR superfamily. We also found that the replacement of residues Arg(301) and Arg(304), localized near the steroid-binding cavity, significantly affects the 3alpha-HSD activity of this enzyme toward 5alpha-DHT and completely abolishes its 17beta-HSD activity on 4-dione. All these results have thus been used to reevaluate the binding mode of this enzyme for androgens.

Disease

Known diseases associated with this structure: Obesity, hyperphagia, and developmental delay OMIM:[600450]

About this Structure

1XJB is a Single protein structure of sequence from Homo sapiens with , , , , and as ligands. Active as 3-alpha-hydroxysteroid dehydrogenase (A-specific), with EC number 1.1.1.213 Full crystallographic information is available from OCA.

Reference

Comparison of crystal structures of human type 3 3alpha-hydroxysteroid dehydrogenase reveals an "induced-fit" mechanism and a conserved basic motif involved in the binding of androgen., Couture JF, de Jesus-Tran KP, Roy AM, Cantin L, Cote PL, Legrand P, Luu-The V, Labrie F, Breton R, Protein Sci. 2005 Jun;14(6):1485-97. PMID:15929998

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