2ajh: Difference between revisions
New page: left|200px<br /><applet load="2ajh" size="450" color="white" frame="true" align="right" spinBox="true" caption="2ajh, resolution 2.40Å" /> '''Crystal structure of... |
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[[Image:2ajh.gif|left|200px]]<br /><applet load="2ajh" size=" | [[Image:2ajh.gif|left|200px]]<br /><applet load="2ajh" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="2ajh, resolution 2.40Å" /> | caption="2ajh, resolution 2.40Å" /> | ||
'''Crystal structure of the editing domain of E. coli leucyl-tRNA synthetase complexes with methionine'''<br /> | '''Crystal structure of the editing domain of E. coli leucyl-tRNA synthetase complexes with methionine'''<br /> | ||
==Overview== | ==Overview== | ||
aaRSs (aminoacyl-tRNA synthetases) are responsible for the covalent | aaRSs (aminoacyl-tRNA synthetases) are responsible for the covalent linking of amino acids to their cognate tRNAs via the aminoacylation reaction and play a vital role in maintaining the fidelity of protein synthesis. LeuRS (leucyl-tRNA synthetase) can link not only the cognate leucine but also the nearly cognate residues Ile and Met to tRNA(Leu). The editing domain of LeuRS deacylates the mischarged Ile-tRNA(Leu) and Met-tRNA(Leu). We report here the crystal structures of ecLeuRS-ED (the editing domain of Escherichia coli LeuRS) in both the apo form and in complexes with Met and Ile at 2.0 A, 2.4 A, and 3.2 A resolution respectively. The editing active site consists of a number of conserved amino acids, which are involved in the precise recognition and binding of the noncognate amino acids. The substrate-binding pocket has a rigid structure which has an optimal stereochemical fit for Ile and Met, but has steric hindrance for leucine. Based on our structural results and previously available biochemical data, we propose that ecLeuRS-ED uses a lock-and-key mechanism to recognize and discriminate between the amino acids. Structural comparison also reveals that all subclass Ia aaRSs share a conserved structure core consisting of the editing domain and conserved residues at the editing active site, suggesting that these enzymes may use a common mechanism for the editing function. | ||
==About this Structure== | ==About this Structure== | ||
2AJH 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 MET as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Leucine--tRNA_ligase Leucine--tRNA ligase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.1.1.4 6.1.1.4] Full crystallographic information is available from [http:// | 2AJH 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=MET:'>MET</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Leucine--tRNA_ligase Leucine--tRNA ligase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.1.1.4 6.1.1.4] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2AJH OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Liao, J.]] | [[Category: Liao, J.]] | ||
[[Category: Liu, Y.]] | [[Category: Liu, Y.]] | ||
[[Category: Wang, E | [[Category: Wang, E D.]] | ||
[[Category: Zhu, B.]] | [[Category: Zhu, B.]] | ||
[[Category: MET]] | [[Category: MET]] | ||
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[[Category: leucyl-trna synthetase]] | [[Category: leucyl-trna synthetase]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:28:05 2008'' | ||
Revision as of 17:28, 21 February 2008
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Crystal structure of the editing domain of E. coli leucyl-tRNA synthetase complexes with methionine
OverviewOverview
aaRSs (aminoacyl-tRNA synthetases) are responsible for the covalent linking of amino acids to their cognate tRNAs via the aminoacylation reaction and play a vital role in maintaining the fidelity of protein synthesis. LeuRS (leucyl-tRNA synthetase) can link not only the cognate leucine but also the nearly cognate residues Ile and Met to tRNA(Leu). The editing domain of LeuRS deacylates the mischarged Ile-tRNA(Leu) and Met-tRNA(Leu). We report here the crystal structures of ecLeuRS-ED (the editing domain of Escherichia coli LeuRS) in both the apo form and in complexes with Met and Ile at 2.0 A, 2.4 A, and 3.2 A resolution respectively. The editing active site consists of a number of conserved amino acids, which are involved in the precise recognition and binding of the noncognate amino acids. The substrate-binding pocket has a rigid structure which has an optimal stereochemical fit for Ile and Met, but has steric hindrance for leucine. Based on our structural results and previously available biochemical data, we propose that ecLeuRS-ED uses a lock-and-key mechanism to recognize and discriminate between the amino acids. Structural comparison also reveals that all subclass Ia aaRSs share a conserved structure core consisting of the editing domain and conserved residues at the editing active site, suggesting that these enzymes may use a common mechanism for the editing function.
About this StructureAbout this Structure
2AJH is a Single protein structure of sequence from Escherichia coli with as ligand. Active as Leucine--tRNA ligase, with EC number 6.1.1.4 Full crystallographic information is available from OCA.
ReferenceReference
Crystal structures of the editing domain of Escherichia coli leucyl-tRNA synthetase and its complexes with Met and Ile reveal a lock-and-key mechanism for amino acid discrimination., Liu Y, Liao J, Zhu B, Wang ED, Ding J, Biochem J. 2006 Mar 1;394(Pt 2):399-407. PMID:16277600
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