2dfv
From Proteopedia
(New page: 200px<br /><applet load="2dfv" size="450" color="white" frame="true" align="right" spinBox="true" caption="2dfv, resolution 2.05Å" /> '''Hyperthermophilic th...) |
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| - | [[Image:2dfv.jpg|left|200px]]<br /><applet load="2dfv" size=" | + | [[Image:2dfv.jpg|left|200px]]<br /><applet load="2dfv" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2dfv, resolution 2.05Å" /> | caption="2dfv, resolution 2.05Å" /> | ||
'''Hyperthermophilic threonine dehydrogenase from Pyrococcus horikoshii'''<br /> | '''Hyperthermophilic threonine dehydrogenase from Pyrococcus horikoshii'''<br /> | ||
==Overview== | ==Overview== | ||
| - | + | L-threonine dehydrogenase (TDH) is an enzyme that catalyzes the oxidation of L-threonine to 2-amino-3-ketobutyrate. We solved the first crystal structure of a medium chain L-threonine dehydrogenase from a hyperthermophilic archaeon, Pyrococcus horikoshii (PhTDH), by the single wavelength anomalous diffraction method using a selenomethionine-substituted enzyme. This recombinant PhTDH is a homo-tetramer in solution. Three monomers of PhTDHs were located in the crystallographic asymmetric unit, however, the crystal structure exhibits a homo-tetramer structure with crystallographic and non-crystallographic 222 symmetry in the cell. Despite the low level of sequence identity to a medium-chain NAD(H)-dependent alcohol dehydrogenase (ADH) and the different substrate specificity, the overall folds of the PhTDH monomer and tetramer are similar to those of the other ADH. Each subunit is composed of two domains: a nicotinamide cofactor (NAD(H))-binding domain and a catalytic domain. The NAD(H)-binding domain contains the alpha/beta Rossmann fold motif, characteristic of the NAD(H)-binding protein. One molecule of PhTDH contains one zinc ion playing a structural role. This metal ion exhibits coordination with four cysteine ligands and some of the ligands are conserved throughout the structural zinc-containing ADHs and TDHs. However, the catalytic zinc ion that is coordinated at the bottom of the cleft in the case of ADH was not observed in the crystal of PhTDH. There is a significant difference in the orientation of the catalytic domain relative to the coenzyme-binding domain that results in a larger interdomain cleft. | |
==About this Structure== | ==About this Structure== | ||
| - | 2DFV is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pyrococcus_horikoshii Pyrococcus horikoshii] with ZN, SO4 and NAD as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/L-threonine_3-dehydrogenase L-threonine 3-dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.1.103 1.1.1.103] Full crystallographic information is available from [http:// | + | 2DFV is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pyrococcus_horikoshii Pyrococcus horikoshii] with <scene name='pdbligand=ZN:'>ZN</scene>, <scene name='pdbligand=SO4:'>SO4</scene> and <scene name='pdbligand=NAD:'>NAD</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/L-threonine_3-dehydrogenase L-threonine 3-dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.1.1.103 1.1.1.103] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2DFV OCA]. |
==Reference== | ==Reference== | ||
| - | The | + | The first crystal structure of L-threonine dehydrogenase., Ishikawa K, Higashi N, Nakamura T, Matsuura T, Nakagawa A, J Mol Biol. 2007 Feb 23;366(3):857-67. Epub 2006 Nov 21. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=17188300 17188300] |
[[Category: L-threonine 3-dehydrogenase]] | [[Category: L-threonine 3-dehydrogenase]] | ||
[[Category: Pyrococcus horikoshii]] | [[Category: Pyrococcus horikoshii]] | ||
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[[Category: threonine dehydrogenase]] | [[Category: threonine dehydrogenase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:58:21 2008'' |
Revision as of 14:58, 21 February 2008
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Hyperthermophilic threonine dehydrogenase from Pyrococcus horikoshii
Overview
L-threonine dehydrogenase (TDH) is an enzyme that catalyzes the oxidation of L-threonine to 2-amino-3-ketobutyrate. We solved the first crystal structure of a medium chain L-threonine dehydrogenase from a hyperthermophilic archaeon, Pyrococcus horikoshii (PhTDH), by the single wavelength anomalous diffraction method using a selenomethionine-substituted enzyme. This recombinant PhTDH is a homo-tetramer in solution. Three monomers of PhTDHs were located in the crystallographic asymmetric unit, however, the crystal structure exhibits a homo-tetramer structure with crystallographic and non-crystallographic 222 symmetry in the cell. Despite the low level of sequence identity to a medium-chain NAD(H)-dependent alcohol dehydrogenase (ADH) and the different substrate specificity, the overall folds of the PhTDH monomer and tetramer are similar to those of the other ADH. Each subunit is composed of two domains: a nicotinamide cofactor (NAD(H))-binding domain and a catalytic domain. The NAD(H)-binding domain contains the alpha/beta Rossmann fold motif, characteristic of the NAD(H)-binding protein. One molecule of PhTDH contains one zinc ion playing a structural role. This metal ion exhibits coordination with four cysteine ligands and some of the ligands are conserved throughout the structural zinc-containing ADHs and TDHs. However, the catalytic zinc ion that is coordinated at the bottom of the cleft in the case of ADH was not observed in the crystal of PhTDH. There is a significant difference in the orientation of the catalytic domain relative to the coenzyme-binding domain that results in a larger interdomain cleft.
About this Structure
2DFV is a Single protein structure of sequence from Pyrococcus horikoshii with , and as ligands. Active as L-threonine 3-dehydrogenase, with EC number 1.1.1.103 Full crystallographic information is available from OCA.
Reference
The first crystal structure of L-threonine dehydrogenase., Ishikawa K, Higashi N, Nakamura T, Matsuura T, Nakagawa A, J Mol Biol. 2007 Feb 23;366(3):857-67. Epub 2006 Nov 21. PMID:17188300
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