This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
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...) |
|||
| Line 1: | Line 1: | ||
| - | [[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== | ||
| Line 19: | Line 19: | ||
[[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
|
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
Page seeded by OCA on Thu Feb 21 12:24:18 2008
