1e6b
From Proteopedia
(New page: 200px<br /><applet load="1e6b" size="450" color="white" frame="true" align="right" spinBox="true" caption="1e6b, resolution 1.65Å" /> '''CRYSTAL STRUCTURE OF...) |
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| - | [[Image:1e6b.jpg|left|200px]]<br /><applet load="1e6b" size=" | + | [[Image:1e6b.jpg|left|200px]]<br /><applet load="1e6b" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1e6b, resolution 1.65Å" /> | caption="1e6b, resolution 1.65Å" /> | ||
'''CRYSTAL STRUCTURE OF A ZETA CLASS GLUTATHIONE S-TRANSFERASE FROM ARABIDOPSIS THALIANA'''<br /> | '''CRYSTAL STRUCTURE OF A ZETA CLASS GLUTATHIONE S-TRANSFERASE FROM ARABIDOPSIS THALIANA'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The cis-trans isomerisation of maleylacetoacetate to fumarylacetoacetate | + | The cis-trans isomerisation of maleylacetoacetate to fumarylacetoacetate is the penultimate step in the tyrosine/phenylalanine catabolic pathway and has recently been shown to be catalysed by glutathione S-transferase enzymes belonging to the zeta class. Given this primary metabolic role it is unsurprising that zeta class glutathione S-transferases are well conserved over a considerable period of evolution, being found in vertebrates, plants, insects and fungi. The structure of this glutathione S-transferase, cloned from Arabidopsis thaliana, has been solved by single isomorphous replacement with anomalous scattering and refined to a final crystallographic R-factor of 19.6% using data from 25.0 A to 1.65 A. The zeta class enzyme adopts the canonical glutathione S-transferase fold and forms a homodimer with each subunit consisting of 221 residues. In agreement with structures of glutathione S-transferases from the theta and phi classes, a serine residue (Ser17) is present in the active site, at a position that would allow it to stabilise the thiolate anion of glutathione. Site-directed mutagenesis of this residue confirms its importance in catalysis. In addition, the role of a highly conserved cysteine residue (Cys19) present in the active site of the zeta class glutathione S-transferase enzymes is discussed. |
==About this Structure== | ==About this Structure== | ||
| - | 1E6B is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Arabidopsis_thaliana Arabidopsis thaliana] with BME 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:// | + | 1E6B is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Arabidopsis_thaliana Arabidopsis thaliana] with <scene name='pdbligand=BME:'>BME</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=1E6B OCA]. |
==Reference== | ==Reference== | ||
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[[Category: transferase]] | [[Category: transferase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:24:18 2008'' |
Revision as of 10:24, 21 February 2008
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CRYSTAL STRUCTURE OF A ZETA CLASS GLUTATHIONE S-TRANSFERASE FROM ARABIDOPSIS THALIANA
Overview
The cis-trans isomerisation of maleylacetoacetate to fumarylacetoacetate is the penultimate step in the tyrosine/phenylalanine catabolic pathway and has recently been shown to be catalysed by glutathione S-transferase enzymes belonging to the zeta class. Given this primary metabolic role it is unsurprising that zeta class glutathione S-transferases are well conserved over a considerable period of evolution, being found in vertebrates, plants, insects and fungi. The structure of this glutathione S-transferase, cloned from Arabidopsis thaliana, has been solved by single isomorphous replacement with anomalous scattering and refined to a final crystallographic R-factor of 19.6% using data from 25.0 A to 1.65 A. The zeta class enzyme adopts the canonical glutathione S-transferase fold and forms a homodimer with each subunit consisting of 221 residues. In agreement with structures of glutathione S-transferases from the theta and phi classes, a serine residue (Ser17) is present in the active site, at a position that would allow it to stabilise the thiolate anion of glutathione. Site-directed mutagenesis of this residue confirms its importance in catalysis. In addition, the role of a highly conserved cysteine residue (Cys19) present in the active site of the zeta class glutathione S-transferase enzymes is discussed.
About this Structure
1E6B is a Single protein structure of sequence from Arabidopsis thaliana with as ligand. Active as Glutathione transferase, with EC number 2.5.1.18 Full crystallographic information is available from OCA.
Reference
The structure of a zeta class glutathione S-transferase from Arabidopsis thaliana: characterisation of a GST with novel active-site architecture and a putative role in tyrosine catabolism., Thom R, Dixon DP, Edwards R, Cole DJ, Lapthorn AJ, J Mol Biol. 2001 May 18;308(5):949-62. PMID:11352584
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