1qv9
From Proteopedia
(New page: 200px<br /><applet load="1qv9" size="450" color="white" frame="true" align="right" spinBox="true" caption="1qv9, resolution 1.54Å" /> '''Coenzyme F420-depend...) |
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| - | [[Image:1qv9.jpg|left|200px]]<br /><applet load="1qv9" size=" | + | [[Image:1qv9.jpg|left|200px]]<br /><applet load="1qv9" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1qv9, resolution 1.54Å" /> | caption="1qv9, resolution 1.54Å" /> | ||
'''Coenzyme F420-dependent methylenetetrahydromethanopterin dehydrogenase (Mtd) from Methanopyrus kandleri: A methanogenic enzyme with an unusual quarternary structure'''<br /> | '''Coenzyme F420-dependent methylenetetrahydromethanopterin dehydrogenase (Mtd) from Methanopyrus kandleri: A methanogenic enzyme with an unusual quarternary structure'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The fourth reaction step of CO(2)-reduction to methane in methanogenic | + | The fourth reaction step of CO(2)-reduction to methane in methanogenic archaea is catalyzed by coenzyme F(420)-dependent methylenetetrahydromethanopterin dehydrogenase (Mtd). We have structurally characterized this enzyme in the selenomethionine-labelled form from the hyperthermophilic methanogenic archaeon Methanopyrus kandleri at 1.54A resolution using the single wavelength anomalous dispersion method for phase determination. Mtd was found to be a homohexameric protein complex that is organized as a trimer of dimers. The fold of the individual subunits is composed of two domains: a larger alpha,beta domain and a smaller helix bundle domain with a short C-terminal beta-sheet segment. In the homohexamer the alpha,beta domains are positioned at the outside of the enzyme, whereas, the helix bundle domains assemble towards the inside to form an unusual quarternary structure with a 12-helix bundle around a 3-fold axis. No structural similarities are detectable to other enzymes with F(420) and/or substituted tetrahydropterins as substrates. The substrate binding sites of F(420) and methylenetetrahydromethanopterin are most likely embedded into a crevice between the domains of one subunit, their isoalloxazine and tetrahydropterin rings being placed inside a pocket formed by this crevice and a loop segment of the adjacent monomer of the dimer. Mtd revealed the highest stability at low salt concentrations of all structurally characterized enzymes from M.kandleri. This finding might be due to the compact quaternary structure that buries 36% of the monomer surface and to the large number of ion pairs. |
==About this Structure== | ==About this Structure== | ||
| - | 1QV9 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Methanopyrus_kandleri Methanopyrus kandleri] with MG as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Methylenetetrahydromethanopterin_dehydrogenase Methylenetetrahydromethanopterin dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.5.99.9 1.5.99.9] Full crystallographic information is available from [http:// | + | 1QV9 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Methanopyrus_kandleri Methanopyrus kandleri] with <scene name='pdbligand=MG:'>MG</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Methylenetetrahydromethanopterin_dehydrogenase Methylenetetrahydromethanopterin dehydrogenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.5.99.9 1.5.99.9] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QV9 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Methylenetetrahydromethanopterin dehydrogenase]] | [[Category: Methylenetetrahydromethanopterin dehydrogenase]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Bartunik, H | + | [[Category: Bartunik, H D.]] |
[[Category: Bourenkov, G.]] | [[Category: Bourenkov, G.]] | ||
[[Category: Ermler, U.]] | [[Category: Ermler, U.]] | ||
| - | [[Category: Hagemeier, C | + | [[Category: Hagemeier, C H.]] |
[[Category: Shima, S.]] | [[Category: Shima, S.]] | ||
| - | [[Category: Thauer, R | + | [[Category: Thauer, R K.]] |
[[Category: MG]] | [[Category: MG]] | ||
[[Category: helix bundle; trimer of dimers]] | [[Category: helix bundle; trimer of dimers]] | ||
[[Category: monomer: alpha/beta domain]] | [[Category: monomer: alpha/beta domain]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:44:02 2008'' |
Revision as of 12:44, 21 February 2008
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Coenzyme F420-dependent methylenetetrahydromethanopterin dehydrogenase (Mtd) from Methanopyrus kandleri: A methanogenic enzyme with an unusual quarternary structure
Overview
The fourth reaction step of CO(2)-reduction to methane in methanogenic archaea is catalyzed by coenzyme F(420)-dependent methylenetetrahydromethanopterin dehydrogenase (Mtd). We have structurally characterized this enzyme in the selenomethionine-labelled form from the hyperthermophilic methanogenic archaeon Methanopyrus kandleri at 1.54A resolution using the single wavelength anomalous dispersion method for phase determination. Mtd was found to be a homohexameric protein complex that is organized as a trimer of dimers. The fold of the individual subunits is composed of two domains: a larger alpha,beta domain and a smaller helix bundle domain with a short C-terminal beta-sheet segment. In the homohexamer the alpha,beta domains are positioned at the outside of the enzyme, whereas, the helix bundle domains assemble towards the inside to form an unusual quarternary structure with a 12-helix bundle around a 3-fold axis. No structural similarities are detectable to other enzymes with F(420) and/or substituted tetrahydropterins as substrates. The substrate binding sites of F(420) and methylenetetrahydromethanopterin are most likely embedded into a crevice between the domains of one subunit, their isoalloxazine and tetrahydropterin rings being placed inside a pocket formed by this crevice and a loop segment of the adjacent monomer of the dimer. Mtd revealed the highest stability at low salt concentrations of all structurally characterized enzymes from M.kandleri. This finding might be due to the compact quaternary structure that buries 36% of the monomer surface and to the large number of ion pairs.
About this Structure
1QV9 is a Single protein structure of sequence from Methanopyrus kandleri with as ligand. Active as Methylenetetrahydromethanopterin dehydrogenase, with EC number 1.5.99.9 Full crystallographic information is available from OCA.
Reference
Coenzyme F420-dependent methylenetetrahydromethanopterin dehydrogenase (Mtd) from Methanopyrus kandleri: a methanogenic enzyme with an unusual quarternary structure., Hagemeier CH, Shima S, Thauer RK, Bourenkov G, Bartunik HD, Ermler U, J Mol Biol. 2003 Oct 3;332(5):1047-57. PMID:14499608
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