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[[Image: | ==CRYSTAL STRUCTURE OF L-GLUTAMINE AND AMPCPP BOUND TO GLUTAMINE AMINOACYL TRNA SYNTHETASE== | ||
<StructureSection load='1o0b' size='340' side='right' caption='[[1o0b]], [[Resolution|resolution]] 2.70Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1o0b]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1O0B OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1O0B FirstGlance]. <br> | |||
</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=AMP:ADENOSINE+MONOPHOSPHATE'>AMP</scene>, <scene name='pdbligand=GLN:GLUTAMINE'>GLN</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene><br> | |||
<tr><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1o0c|1o0c]], [[1qtq|1qtq]]</td></tr> | |||
<tr><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">GLNS ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli])</td></tr> | |||
<tr><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Glutamine--tRNA_ligase Glutamine--tRNA ligase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.1.1.18 6.1.1.18] </span></td></tr> | |||
<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1o0b FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1o0b OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1o0b RCSB], [http://www.ebi.ac.uk/pdbsum/1o0b PDBsum]</span></td></tr> | |||
<table> | |||
== Evolutionary Conservation == | |||
[[Image:Consurf_key_small.gif|200px|right]] | |||
Check<jmol> | |||
<jmolCheckbox> | |||
<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/o0/1o0b_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | |||
<text>to colour the structure by Evolutionary Conservation</text> | |||
</jmolCheckbox> | |||
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/chain_selection.php?pdb_ID=2ata ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
The 2.5 A crystal structure of Escherichia coli glutaminyl-tRNA synthetase in a quaternary complex with tRNA(Gln), an ATP analog and glutamate reveals that the non-cognate amino acid adopts a distinct binding mode within the active site cleft. In contrast to the binding of cognate glutamine, one oxygen of the charged glutamate carboxylate group makes a direct ion-pair interaction with the strictly conserved Arg30 residue located in the first half of the dinucleotide fold domain. The nucleophilic alpha-carboxylate moiety of glutamate is mispositioned with respect to both the ATP alpha-phosphate and terminal tRNA ribose groups, suggesting that a component of amino acid discrimination resides at the catalytic step of the reaction. Further, the other side-chain carboxylate oxygen of glutamate is found in a position identical to that previously proposed to be occupied by the NH(2) group of the cognate glutamine substrate. At this position, the glutamate oxygen accepts hydrogen bonds from the hydroxyl moiety of Tyr211 and a water molecule. These findings demonstrate that amino acid specificity by GlnRS cannot arise from hydrogen bonds donated by the cognate glutamine amide to these same moieties, as previously suggested. Instead, Arg30 functions as a negative determinant to drive binding of non-cognate glutamate into a non-productive orientation. The poorly differentiated cognate amino acid-binding site in GlnRS may be a consequence of the late emergence of this enzyme from the eukaryotic lineage of glutamyl-tRNA synthetases. | |||
Amino acid discrimination by a class I aminoacyl-tRNA synthetase specified by negative determinants.,Bullock TL, Uter N, Nissan TA, Perona JJ J Mol Biol. 2003 Apr 25;328(2):395-408. PMID:12691748<ref>PMID:12691748</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | ==See Also== | ||
*[[Aminoacyl tRNA Synthetase|Aminoacyl tRNA Synthetase]] | *[[Aminoacyl tRNA Synthetase|Aminoacyl tRNA Synthetase]] | ||
== References == | |||
== | <references/> | ||
< | __TOC__ | ||
</StructureSection> | |||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Glutamine--tRNA ligase]] | [[Category: Glutamine--tRNA ligase]] | ||
Revision as of 19:31, 28 September 2014
CRYSTAL STRUCTURE OF L-GLUTAMINE AND AMPCPP BOUND TO GLUTAMINE AMINOACYL TRNA SYNTHETASECRYSTAL STRUCTURE OF L-GLUTAMINE AND AMPCPP BOUND TO GLUTAMINE AMINOACYL TRNA SYNTHETASE
Structural highlights
Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe 2.5 A crystal structure of Escherichia coli glutaminyl-tRNA synthetase in a quaternary complex with tRNA(Gln), an ATP analog and glutamate reveals that the non-cognate amino acid adopts a distinct binding mode within the active site cleft. In contrast to the binding of cognate glutamine, one oxygen of the charged glutamate carboxylate group makes a direct ion-pair interaction with the strictly conserved Arg30 residue located in the first half of the dinucleotide fold domain. The nucleophilic alpha-carboxylate moiety of glutamate is mispositioned with respect to both the ATP alpha-phosphate and terminal tRNA ribose groups, suggesting that a component of amino acid discrimination resides at the catalytic step of the reaction. Further, the other side-chain carboxylate oxygen of glutamate is found in a position identical to that previously proposed to be occupied by the NH(2) group of the cognate glutamine substrate. At this position, the glutamate oxygen accepts hydrogen bonds from the hydroxyl moiety of Tyr211 and a water molecule. These findings demonstrate that amino acid specificity by GlnRS cannot arise from hydrogen bonds donated by the cognate glutamine amide to these same moieties, as previously suggested. Instead, Arg30 functions as a negative determinant to drive binding of non-cognate glutamate into a non-productive orientation. The poorly differentiated cognate amino acid-binding site in GlnRS may be a consequence of the late emergence of this enzyme from the eukaryotic lineage of glutamyl-tRNA synthetases. Amino acid discrimination by a class I aminoacyl-tRNA synthetase specified by negative determinants.,Bullock TL, Uter N, Nissan TA, Perona JJ J Mol Biol. 2003 Apr 25;328(2):395-408. PMID:12691748[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences |
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