1x6m
From Proteopedia
(New page: 200px<br /><applet load="1x6m" size="450" color="white" frame="true" align="right" spinBox="true" caption="1x6m, resolution 2.35Å" /> '''Crystal structure of...) |
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- | [[Image:1x6m.jpg|left|200px]]<br /><applet load="1x6m" size=" | + | [[Image:1x6m.jpg|left|200px]]<br /><applet load="1x6m" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1x6m, resolution 2.35Å" /> | caption="1x6m, resolution 2.35Å" /> | ||
'''Crystal structure of the glutathione-dependent formaldehyde-activating enzyme (Gfa)'''<br /> | '''Crystal structure of the glutathione-dependent formaldehyde-activating enzyme (Gfa)'''<br /> | ||
==Overview== | ==Overview== | ||
- | The crystal structures of glutathione-dependent formaldehyde-activating | + | The crystal structures of glutathione-dependent formaldehyde-activating enzyme (Gfa) from Paracoccus denitrificans, which catalyzes the formation of S-hydroxymethylglutathione from formaldehyde and glutathione, and its complex with glutathione (Gfa-GTT) have been determined. Gfa has a new fold with two zinc-sulfur centers, one that is structural (zinc tetracoordinated) and one catalytic (zinc apparently tricoordinated). In Gfa-GTT, the catalytic zinc is displaced due to disulfide bond formation of glutathione with one of the zinc-coordinating cysteines. Soaking crystals of Gfa-GTT with formaldehyde restores the holoenzyme. Accordingly, the displaced zinc forms a complex by scavenging formaldehyde and glutathione. The activation of formaldehyde and of glutathione in this zinc complex favors the final nucleophilic addition, followed by relocation of zinc in the catalytic site. Therefore, the structures of Gfa and Gfa-GTT draw the critical association between a dynamic zinc redox switch and a nucleophilic addition as a new facet of the redox activity of zinc-sulfur sites. |
==About this Structure== | ==About this Structure== | ||
- | 1X6M is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Paracoccus_denitrificans Paracoccus denitrificans] with ZN, SO4 and GOL as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1X6M is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Paracoccus_denitrificans Paracoccus denitrificans] with <scene name='pdbligand=ZN:'>ZN</scene>, <scene name='pdbligand=SO4:'>SO4</scene> and <scene name='pdbligand=GOL:'>GOL</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1X6M OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Becker, S.]] | [[Category: Becker, S.]] | ||
- | [[Category: Neculai, A | + | [[Category: Neculai, A M.]] |
[[Category: Neculai, D.]] | [[Category: Neculai, D.]] | ||
- | [[Category: Vorholt, J | + | [[Category: Vorholt, J A.]] |
[[Category: GOL]] | [[Category: GOL]] | ||
[[Category: SO4]] | [[Category: SO4]] | ||
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[[Category: zn-enzyme]] | [[Category: zn-enzyme]] | ||
- | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:51:35 2008'' |
Revision as of 13:51, 21 February 2008
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Crystal structure of the glutathione-dependent formaldehyde-activating enzyme (Gfa)
Overview
The crystal structures of glutathione-dependent formaldehyde-activating enzyme (Gfa) from Paracoccus denitrificans, which catalyzes the formation of S-hydroxymethylglutathione from formaldehyde and glutathione, and its complex with glutathione (Gfa-GTT) have been determined. Gfa has a new fold with two zinc-sulfur centers, one that is structural (zinc tetracoordinated) and one catalytic (zinc apparently tricoordinated). In Gfa-GTT, the catalytic zinc is displaced due to disulfide bond formation of glutathione with one of the zinc-coordinating cysteines. Soaking crystals of Gfa-GTT with formaldehyde restores the holoenzyme. Accordingly, the displaced zinc forms a complex by scavenging formaldehyde and glutathione. The activation of formaldehyde and of glutathione in this zinc complex favors the final nucleophilic addition, followed by relocation of zinc in the catalytic site. Therefore, the structures of Gfa and Gfa-GTT draw the critical association between a dynamic zinc redox switch and a nucleophilic addition as a new facet of the redox activity of zinc-sulfur sites.
About this Structure
1X6M is a Single protein structure of sequence from Paracoccus denitrificans with , and as ligands. Full crystallographic information is available from OCA.
Reference
A dynamic zinc redox switch., Neculai AM, Neculai D, Griesinger C, Vorholt JA, Becker S, J Biol Chem. 2005 Jan 28;280(4):2826-30. Epub 2004 Nov 17. PMID:15548539
Page seeded by OCA on Thu Feb 21 15:51:35 2008
Categories: Paracoccus denitrificans | Single protein | Becker, S. | Neculai, A M. | Neculai, D. | Vorholt, J A. | GOL | SO4 | ZN | 3 10 helix | Formaldehyde | Zn-enzyme