1ps9
From Proteopedia
(New page: 200px<br /><applet load="1ps9" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ps9, resolution 2.2Å" /> '''The Crystal Structure...) |
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| - | [[Image:1ps9.jpg|left|200px]]<br /><applet load="1ps9" size=" | + | [[Image:1ps9.jpg|left|200px]]<br /><applet load="1ps9" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1ps9, resolution 2.2Å" /> | caption="1ps9, resolution 2.2Å" /> | ||
'''The Crystal Structure and Reaction Mechanism of E. coli 2,4-Dienoyl CoA Reductase'''<br /> | '''The Crystal Structure and Reaction Mechanism of E. coli 2,4-Dienoyl CoA Reductase'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Escherichia coli 2,4-dienoyl-CoA reductase is an iron-sulfur flavoenzyme | + | Escherichia coli 2,4-dienoyl-CoA reductase is an iron-sulfur flavoenzyme required for the metabolism of unsaturated fatty acids with double bonds at even carbon positions. The enzyme contains FMN, FAD, and a 4Fe-4S cluster and exhibits sequence homology to another iron-sulfur flavoprotein, trimethylamine dehydrogenase. It also requires NADPH as an electron source, resulting in reduction of the C4-C5 double bond of the acyl chain of the CoA thioester substrate. The structure presented here of a ternary complex of E. coli 2,4-dienoyl-CoA reductase with NADP+ and a fatty acyl-CoA substrate reveals a possible mechanism for substrate reduction and provides details of a plausible electron transfer mechanism involving both flavins and the iron-sulfur cluster. The reaction is initiated by hydride transfer from NADPH to FAD, which in turn transfers electrons, one at a time, to FMN via the 4Fe-4S cluster. In the final stages of the reaction, the fully reduced FMN provides a hydride ion to the C5 atom of substrate, and Tyr-166 and His-252 are proposed to form a catalytic dyad that protonates the C4 atom of the substrate and complete the reaction. Inspection of the substrate binding pocket explains the relative promiscuity of the enzyme, catalyzing reduction of both 2-trans,4-cis- and 2-trans,4-trans-dienoyl-CoA thioesters. |
==About this Structure== | ==About this Structure== | ||
| - | 1PS9 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with CL, SF4, FAD, FMN, NAP and MDE as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/2,4-dienoyl-CoA_reductase_(NADPH) 2,4-dienoyl-CoA reductase (NADPH)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.3.1.34 1.3.1.34] Full crystallographic information is available from [http:// | + | 1PS9 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=CL:'>CL</scene>, <scene name='pdbligand=SF4:'>SF4</scene>, <scene name='pdbligand=FAD:'>FAD</scene>, <scene name='pdbligand=FMN:'>FMN</scene>, <scene name='pdbligand=NAP:'>NAP</scene> and <scene name='pdbligand=MDE:'>MDE</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/2,4-dienoyl-CoA_reductase_(NADPH) 2,4-dienoyl-CoA reductase (NADPH)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.3.1.34 1.3.1.34] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1PS9 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Hubbard, P | + | [[Category: Hubbard, P A.]] |
| - | [[Category: Kim, J | + | [[Category: Kim, J J.]] |
[[Category: Liang, X.]] | [[Category: Liang, X.]] | ||
[[Category: Schulz, H.]] | [[Category: Schulz, H.]] | ||
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[[Category: tim barrel]] | [[Category: tim barrel]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:32:03 2008'' |
Revision as of 12:32, 21 February 2008
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The Crystal Structure and Reaction Mechanism of E. coli 2,4-Dienoyl CoA Reductase
Overview
Escherichia coli 2,4-dienoyl-CoA reductase is an iron-sulfur flavoenzyme required for the metabolism of unsaturated fatty acids with double bonds at even carbon positions. The enzyme contains FMN, FAD, and a 4Fe-4S cluster and exhibits sequence homology to another iron-sulfur flavoprotein, trimethylamine dehydrogenase. It also requires NADPH as an electron source, resulting in reduction of the C4-C5 double bond of the acyl chain of the CoA thioester substrate. The structure presented here of a ternary complex of E. coli 2,4-dienoyl-CoA reductase with NADP+ and a fatty acyl-CoA substrate reveals a possible mechanism for substrate reduction and provides details of a plausible electron transfer mechanism involving both flavins and the iron-sulfur cluster. The reaction is initiated by hydride transfer from NADPH to FAD, which in turn transfers electrons, one at a time, to FMN via the 4Fe-4S cluster. In the final stages of the reaction, the fully reduced FMN provides a hydride ion to the C5 atom of substrate, and Tyr-166 and His-252 are proposed to form a catalytic dyad that protonates the C4 atom of the substrate and complete the reaction. Inspection of the substrate binding pocket explains the relative promiscuity of the enzyme, catalyzing reduction of both 2-trans,4-cis- and 2-trans,4-trans-dienoyl-CoA thioesters.
About this Structure
1PS9 is a Single protein structure of sequence from Escherichia coli with , , , , and as ligands. Active as 2,4-dienoyl-CoA reductase (NADPH), with EC number 1.3.1.34 Full crystallographic information is available from OCA.
Reference
The crystal structure and reaction mechanism of Escherichia coli 2,4-dienoyl-CoA reductase., Hubbard PA, Liang X, Schulz H, Kim JJ, J Biol Chem. 2003 Sep 26;278(39):37553-60. Epub 2003 Jul 2. PMID:12840019
Page seeded by OCA on Thu Feb 21 14:32:03 2008
Categories: 2,4-dienoyl-CoA reductase (NADPH) | Escherichia coli | Single protein | Hubbard, P A. | Kim, J J. | Liang, X. | Schulz, H. | CL | FAD | FMN | MDE | NAP | SF4 | Electron transfer | Flavin | Flavodoxin | Hydride transfer | Iron-sulfur | Tim barrel
