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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2
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pubmed:dateCreated |
1996-2-16
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pubmed:abstractText |
Glutathione S-transferases (GST) are a family of multifunctional enzymes involved in the metabolization of a broad variety of xenobiotics and reactive endogenous compounds. The interest in plant glutathione S-transferases may be attributed to their agronomic value, since it has been demonstrated that glutathione conjugation for a variety of herbicides is the major resistance and selectivity factor in plants. The three-dimensional structure of glutathione S-transferase from the plant Arabidopsis thaliana has been solved by multiple isomorphous replacement and multiwavelength anomalous dispersion techniques at 3 A resolution and refined to a final crystallographic R-factor of 17.5% using data from 8 to 2.2 A resolution. The enzyme forms a dimer of two identical subunits each consisting of 211 residues. Each subunit is characterized by the GST-typical modular structure with two spatially distinct domains. Domain I consists of a central four-stranded beta-sheet flanked on one side by two alpha-helices and on the other side by an irregular segment containing three short 3(10)-helices, while domain II is entirely helical. The dimeric molecule is globular with a prominent large cavity formed between the two subunits. The active site is located in a cleft situated between domains I and II and each subunit binds two molecules of a competitive inhibitor S-hexylglutathione. Both hexyl moieties are oriented parallel and fill the H-subsite of the enzyme's active site. The glutathione peptide of one inhibitor, termed productive binding, occupies the G-subsite with multiple interactions similar to those observed for other glutathione S-transferases, while the glutathione backbone of the second inhibitor, termed unproductive binding, exhibits only weak interactions mediated by two polar contacts. A most striking difference from the mammalian glutathione S-transferases, which share a conserved catalytic tyrosine residue, is the lack of this tyrosine in the active site of the plant glutathione S-transferase.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Enzyme Inhibitors,
http://linkedlifedata.com/resource/pubmed/chemical/Glutathione,
http://linkedlifedata.com/resource/pubmed/chemical/Glutathione Transferase,
http://linkedlifedata.com/resource/pubmed/chemical/Herbicides,
http://linkedlifedata.com/resource/pubmed/chemical/hexylglutathione
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pubmed:status |
MEDLINE
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pubmed:month |
Jan
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pubmed:issn |
0022-2836
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
19
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pubmed:volume |
255
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
289-309
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pubmed:dateRevised |
2000-12-18
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pubmed:meshHeading |
pubmed-meshheading:8551521-Amino Acid Sequence,
pubmed-meshheading:8551521-Arabidopsis,
pubmed-meshheading:8551521-Binding Sites,
pubmed-meshheading:8551521-Crystallography, X-Ray,
pubmed-meshheading:8551521-Enzyme Inhibitors,
pubmed-meshheading:8551521-Glutathione,
pubmed-meshheading:8551521-Glutathione Transferase,
pubmed-meshheading:8551521-Herbicides,
pubmed-meshheading:8551521-Models, Molecular,
pubmed-meshheading:8551521-Molecular Sequence Data,
pubmed-meshheading:8551521-Protein Conformation,
pubmed-meshheading:8551521-Protein Structure, Secondary,
pubmed-meshheading:8551521-Sequence Alignment
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pubmed:year |
1996
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pubmed:articleTitle |
Three-dimensional structure of glutathione S-transferase from Arabidopsis thaliana at 2.2 A resolution: structural characterization of herbicide-conjugating plant glutathione S-transferases and a novel active site architecture.
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pubmed:affiliation |
Bayer AG, GB Pflanzenschutz (PF-F Biotechnologie) Pflanzenschutzzentrum Monheim, Leverkusen, Germany.
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pubmed:publicationType |
Journal Article
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