2f8f
From Proteopedia
(New page: 200px<br /><applet load="2f8f" size="450" color="white" frame="true" align="right" spinBox="true" caption="2f8f, resolution 2.10Å" /> '''Crystal structure of...) |
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| - | [[Image:2f8f.gif|left|200px]]<br /><applet load="2f8f" size=" | + | [[Image:2f8f.gif|left|200px]]<br /><applet load="2f8f" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2f8f, resolution 2.10Å" /> | caption="2f8f, resolution 2.10Å" /> | ||
'''Crystal structure of the Y10F mutant of the gluathione s-transferase from schistosoma haematobium'''<br /> | '''Crystal structure of the Y10F mutant of the gluathione s-transferase from schistosoma haematobium'''<br /> | ||
==Overview== | ==Overview== | ||
| - | During turnover, the catalytic tyrosine residue (Tyr10) of the sigma class | + | During turnover, the catalytic tyrosine residue (Tyr10) of the sigma class Schistosoma haematobium wild-type glutathione-S-transferase is expected to switch alternately in and out of the reduced glutathione-binding site (G-site). The Tyrout10 conformer forms a pi-cation interaction with the guanidinium group of Arg21. As in other similar glutathione-S-transferases, the catalytic Tyr has a low pKa of 7.2. In order to investigate the catalytic role of Tyr10, and the structural and functional roles of Arg21, we carried out structural studies on two Arg21 mutants (R21L and R21Q) and a Tyr10 mutant, Y10F. Our crystallographic data for the two Arg21 mutants indicate that only the Tyrout10 conformation is populated, thereby excluding a role of Arg21 in the stabilisation of the out conformation. However, Arg21 was confirmed to be catalytically important and essential for the low pKa of Tyr10. Upon comparison with structural data generated for reduced glutathione-bound and inhibitor-bound wild-type enzymes, it was observed that the orientations of Tyr10 and Arg35 are concerted and that, upon ligand binding, minor rearrangements occur within conserved residues in the active site loop. These rearrangements are coupled to quaternary rigid-body movements at the dimer interface and alterations in the localisation and structural order of the C-terminal domain. |
==About this Structure== | ==About this Structure== | ||
| - | 2F8F is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Schistosoma_haematobium Schistosoma haematobium] with GTT as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Glutathione_transferase Glutathione transferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.5.1.18 2.5.1.18] Full crystallographic information is available from [http:// | + | 2F8F is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Schistosoma_haematobium Schistosoma haematobium] with <scene name='pdbligand=GTT:'>GTT</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Glutathione_transferase Glutathione transferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.5.1.18 2.5.1.18] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2F8F OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Bellelli, A.]] | [[Category: Bellelli, A.]] | ||
[[Category: Brunori, M.]] | [[Category: Brunori, M.]] | ||
| - | [[Category: Gourlay, L | + | [[Category: Gourlay, L J.]] |
| - | [[Category: Miele, A | + | [[Category: Miele, A E.]] |
[[Category: GTT]] | [[Category: GTT]] | ||
[[Category: homodimer]] | [[Category: homodimer]] | ||
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[[Category: thioredoxin fold]] | [[Category: thioredoxin fold]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:18:46 2008'' |
Revision as of 15:18, 21 February 2008
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Crystal structure of the Y10F mutant of the gluathione s-transferase from schistosoma haematobium
Overview
During turnover, the catalytic tyrosine residue (Tyr10) of the sigma class Schistosoma haematobium wild-type glutathione-S-transferase is expected to switch alternately in and out of the reduced glutathione-binding site (G-site). The Tyrout10 conformer forms a pi-cation interaction with the guanidinium group of Arg21. As in other similar glutathione-S-transferases, the catalytic Tyr has a low pKa of 7.2. In order to investigate the catalytic role of Tyr10, and the structural and functional roles of Arg21, we carried out structural studies on two Arg21 mutants (R21L and R21Q) and a Tyr10 mutant, Y10F. Our crystallographic data for the two Arg21 mutants indicate that only the Tyrout10 conformation is populated, thereby excluding a role of Arg21 in the stabilisation of the out conformation. However, Arg21 was confirmed to be catalytically important and essential for the low pKa of Tyr10. Upon comparison with structural data generated for reduced glutathione-bound and inhibitor-bound wild-type enzymes, it was observed that the orientations of Tyr10 and Arg35 are concerted and that, upon ligand binding, minor rearrangements occur within conserved residues in the active site loop. These rearrangements are coupled to quaternary rigid-body movements at the dimer interface and alterations in the localisation and structural order of the C-terminal domain.
About this Structure
2F8F is a Single protein structure of sequence from Schistosoma haematobium with as ligand. Active as Glutathione transferase, with EC number 2.5.1.18 Full crystallographic information is available from OCA.
Reference
Probing the mechanism of GSH activation in Schistosoma haematobium glutathione-S-transferase by site-directed mutagenesis and X-ray crystallography., Baiocco P, Gourlay LJ, Angelucci F, Fontaine J, Herve M, Miele AE, Trottein F, Brunori M, Bellelli A, J Mol Biol. 2006 Jul 14;360(3):678-89. Epub 2006 Jun 2. PMID:16777141
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