1o0s
From Proteopedia
(New page: 200px<br /><applet load="1o0s" size="450" color="white" frame="true" align="right" spinBox="true" caption="1o0s, resolution 2.0Å" /> '''Crystal Structure of ...) |
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| - | [[Image:1o0s.gif|left|200px]]<br /><applet load="1o0s" size=" | + | [[Image:1o0s.gif|left|200px]]<br /><applet load="1o0s" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1o0s, resolution 2.0Å" /> | caption="1o0s, resolution 2.0Å" /> | ||
'''Crystal Structure of Ascaris suum Malic Enzyme Complexed with NADH'''<br /> | '''Crystal Structure of Ascaris suum Malic Enzyme Complexed with NADH'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The crystal structure of the mitochondrial NAD-malic enzyme from Ascaris | + | The crystal structure of the mitochondrial NAD-malic enzyme from Ascaris suum, in a quaternary complex with NADH, tartronate, and magnesium has been determined to 2.0-A resolution. The structure closely resembles the previously determined structure of the same enzyme in binary complex with NAD. However, a significant difference is observed within the coenzyme-binding pocket of the active site with the nicotinamide ring of NADH molecule rotating by 198 degrees over the C-1-N-1 bond into the active site without causing significant movement of the other catalytic residues. The implications of this conformational change in the nicotinamide ring to the catalytic mechanism are discussed. The structure also reveals a binding pocket for the divalent metal ion in the active site and a binding site for tartronate located in a highly positively charged environment within the subunit interface that is distinct from the active site. The tartronate binding site, presumably an allosteric site for the activator fumarate, shows striking similarities and differences with the activator site of the human NAD-malic enzyme that has been reported recently. Thus, the structure provides additional insights into the catalytic as well as the allosteric mechanisms of the enzyme. |
==About this Structure== | ==About this Structure== | ||
| - | 1O0S is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Ascaris_suum Ascaris suum] with TTN and NAI as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Malate_dehydrogenase_(oxaloacetate-decarboxylating) Malate dehydrogenase (oxaloacetate-decarboxylating)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.1.38 1.1.1.38] Full crystallographic information is available from [http:// | + | 1O0S is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Ascaris_suum Ascaris suum] with <scene name='pdbligand=TTN:'>TTN</scene> and <scene name='pdbligand=NAI:'>NAI</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Malate_dehydrogenase_(oxaloacetate-decarboxylating) Malate dehydrogenase (oxaloacetate-decarboxylating)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.1.38 1.1.1.38] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1O0S OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Malate dehydrogenase (oxaloacetate-decarboxylating)]] | [[Category: Malate dehydrogenase (oxaloacetate-decarboxylating)]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Coleman, D | + | [[Category: Coleman, D E.]] |
| - | [[Category: Cook, P | + | [[Category: Cook, P F.]] |
| - | [[Category: Harris, B | + | [[Category: Harris, B G.]] |
| - | [[Category: Karsten, W | + | [[Category: Karsten, W E.]] |
| - | [[Category: Rao, G | + | [[Category: Rao, G S.]] |
[[Category: NAI]] | [[Category: NAI]] | ||
[[Category: TTN]] | [[Category: TTN]] | ||
| Line 27: | Line 27: | ||
[[Category: rossmann fold]] | [[Category: rossmann fold]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:12:07 2008'' |
Revision as of 12:12, 21 February 2008
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Crystal Structure of Ascaris suum Malic Enzyme Complexed with NADH
Overview
The crystal structure of the mitochondrial NAD-malic enzyme from Ascaris suum, in a quaternary complex with NADH, tartronate, and magnesium has been determined to 2.0-A resolution. The structure closely resembles the previously determined structure of the same enzyme in binary complex with NAD. However, a significant difference is observed within the coenzyme-binding pocket of the active site with the nicotinamide ring of NADH molecule rotating by 198 degrees over the C-1-N-1 bond into the active site without causing significant movement of the other catalytic residues. The implications of this conformational change in the nicotinamide ring to the catalytic mechanism are discussed. The structure also reveals a binding pocket for the divalent metal ion in the active site and a binding site for tartronate located in a highly positively charged environment within the subunit interface that is distinct from the active site. The tartronate binding site, presumably an allosteric site for the activator fumarate, shows striking similarities and differences with the activator site of the human NAD-malic enzyme that has been reported recently. Thus, the structure provides additional insights into the catalytic as well as the allosteric mechanisms of the enzyme.
About this Structure
1O0S is a Single protein structure of sequence from Ascaris suum with and as ligands. Active as Malate dehydrogenase (oxaloacetate-decarboxylating), with EC number 1.1.1.38 Full crystallographic information is available from OCA.
Reference
Crystallographic studies on Ascaris suum NAD-malic enzyme bound to reduced cofactor and identification of an effector site., Rao GS, Coleman DE, Karsten WE, Cook PF, Harris BG, J Biol Chem. 2003 Sep 26;278(39):38051-8. Epub 2003 Jul 9. PMID:12853453
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