1x8r
From Proteopedia
(New page: 200px<br /><applet load="1x8r" size="450" color="white" frame="true" align="right" spinBox="true" caption="1x8r, resolution 1.5Å" /> '''EPSPS liganded with t...) |
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| - | [[Image:1x8r.gif|left|200px]]<br /><applet load="1x8r" size=" | + | [[Image:1x8r.gif|left|200px]]<br /><applet load="1x8r" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1x8r, resolution 1.5Å" /> | caption="1x8r, resolution 1.5Å" /> | ||
'''EPSPS liganded with the (S)-phosphonate analog of the tetrahedral reaction intermediate'''<br /> | '''EPSPS liganded with the (S)-phosphonate analog of the tetrahedral reaction intermediate'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) catalyzes | + | The enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) catalyzes the penultimate step of the shikimate pathway and is the target of the broad-spectrum herbicide glyphosate. Since the functionality of the shikimate pathway is vital not only for plants but also for microorganisms, EPSPS is considered a prospective target for the development of novel antibiotics. We have kinetically analyzed and determined the crystal structures of Escherichia coli EPSPS inhibited by (R)- and (S)-configured phosphonate analogues of the tetrahedral reaction intermediate. Both diastereomers are competitive inhibitors with respect to the substrates of the EPSPS reaction, shikimate-3-phosphate (S3P) and phosphoenolpyruvate (PEP). Remarkably, the (S)-phosphonate (K(iS3P) = 750 nM), whose configuration corresponds to that of the genuine tetrahedral intermediate, is a much weaker inhibitor than the (R)-phosphonate analogue (K(iS3P) = 16 nM). The crystal structures of EPSPS liganded with the (S)- and (R)-phosphonates, at 1.5 and 1.9 A resolution, respectively, revealed that binding of the (R)-phosphonate induces conformational changes of the strictly conserved residues Arg124 and Glu341 within the active site. This appears to give rise to substantial structural alterations in the amino-terminal globular domain of the enzyme. By contrast, binding of the (S)-phosphonate renders the enzyme structure unchanged. Thus, EPSPS may facilitate the tight binding of structurally diverse ligands through conformational flexibility. Molecular docking calculations did not explain why the (R)-phosphonate is the better inhibitor. Therefore, we propose that the structural events during the open-closed transition of EPSPS are altered as a result of inhibitor action. |
==About this Structure== | ==About this Structure== | ||
| - | 1X8R is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with SC1 and FMT as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/3-phosphoshikimate_1-carboxyvinyltransferase 3-phosphoshikimate 1-carboxyvinyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.5.1.19 2.5.1.19] Full crystallographic information is available from [http:// | + | 1X8R is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=SC1:'>SC1</scene> and <scene name='pdbligand=FMT:'>FMT</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/3-phosphoshikimate_1-carboxyvinyltransferase 3-phosphoshikimate 1-carboxyvinyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.5.1.19 2.5.1.19] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1X8R OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Alberg, D | + | [[Category: Alberg, D G.]] |
| - | [[Category: Bartlett, P | + | [[Category: Bartlett, P A.]] |
[[Category: Becker, A.]] | [[Category: Becker, A.]] | ||
| - | [[Category: Healy, M | + | [[Category: Healy, M L.]] |
| - | [[Category: Priestman, M | + | [[Category: Priestman, M A.]] |
[[Category: Schonbrunn, E.]] | [[Category: Schonbrunn, E.]] | ||
[[Category: FMT]] | [[Category: FMT]] | ||
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[[Category: inside-out alpha-beta barrel]] | [[Category: inside-out alpha-beta barrel]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:52:11 2008'' |
Revision as of 13:52, 21 February 2008
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EPSPS liganded with the (S)-phosphonate analog of the tetrahedral reaction intermediate
Overview
The enzyme 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) catalyzes the penultimate step of the shikimate pathway and is the target of the broad-spectrum herbicide glyphosate. Since the functionality of the shikimate pathway is vital not only for plants but also for microorganisms, EPSPS is considered a prospective target for the development of novel antibiotics. We have kinetically analyzed and determined the crystal structures of Escherichia coli EPSPS inhibited by (R)- and (S)-configured phosphonate analogues of the tetrahedral reaction intermediate. Both diastereomers are competitive inhibitors with respect to the substrates of the EPSPS reaction, shikimate-3-phosphate (S3P) and phosphoenolpyruvate (PEP). Remarkably, the (S)-phosphonate (K(iS3P) = 750 nM), whose configuration corresponds to that of the genuine tetrahedral intermediate, is a much weaker inhibitor than the (R)-phosphonate analogue (K(iS3P) = 16 nM). The crystal structures of EPSPS liganded with the (S)- and (R)-phosphonates, at 1.5 and 1.9 A resolution, respectively, revealed that binding of the (R)-phosphonate induces conformational changes of the strictly conserved residues Arg124 and Glu341 within the active site. This appears to give rise to substantial structural alterations in the amino-terminal globular domain of the enzyme. By contrast, binding of the (S)-phosphonate renders the enzyme structure unchanged. Thus, EPSPS may facilitate the tight binding of structurally diverse ligands through conformational flexibility. Molecular docking calculations did not explain why the (R)-phosphonate is the better inhibitor. Therefore, we propose that the structural events during the open-closed transition of EPSPS are altered as a result of inhibitor action.
About this Structure
1X8R is a Single protein structure of sequence from Escherichia coli with and as ligands. Active as 3-phosphoshikimate 1-carboxyvinyltransferase, with EC number 2.5.1.19 Full crystallographic information is available from OCA.
Reference
Interaction of phosphonate analogues of the tetrahedral reaction intermediate with 5-enolpyruvylshikimate-3-phosphate synthase in atomic detail., Priestman MA, Healy ML, Becker A, Alberg DG, Bartlett PA, Lushington GH, Schonbrunn E, Biochemistry. 2005 Mar 8;44(9):3241-8. PMID:15736934
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