1o0c

CRYSTAL STRUCTURE OF L-GLUTAMATE AND AMPCPP BOUND TO GLUTAMINE AMINOACYL TRNA SYNTHETASE

spinqualitylabelsall models 1o0c, resolution 2.70Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1o0c is a 2 chain structure with sequence from "bacillus_coli"_migula_1895 "bacillus coli" migula 1895. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: AMP, GLU, SO4 Related: 1o0b, 1qtq Gene: GLNS ("Bacillus coli" Migula 1895) Activity: Glutamine--tRNA ligase, with EC number 6.1.1.18 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum 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 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 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Aminoacyl tRNA Synthetase

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