2amc: Difference between revisions

Revision as of 17:28, 21 February 2008

Crystal structure of Phenylalanyl-tRNA synthetase complexed with L-tyrosine

OverviewOverview

Aminoacyl-tRNA synthetases (aaRSs) exert control over the faithful transfer of amino acids onto cognate tRNAs. Since chemical structures of various amino acids closely resemble each other, it is difficult to discriminate between them. Editing activity has been evolved by certain aaRSs to resolve the problem. In this study, we determined the crystal structures of complexes of T. thermophilus phenylalanyl-tRNA synthetase (PheRS) with L-tyrosine, p-chloro-phenylalanine, and a nonhydrolyzable tyrosyl-adenylate analog. The structures demonstrate plasticity of the synthetic site capable of binding substrates larger than phenylalanine and provide a structural basis for the proofreading mechanism. The editing site is localized at the B3/B4 interface, 35 A from the synthetic site. Glubeta334 plays a crucial role in the specific recognition of the Tyr moiety in the editing site. The tyrosyl-adenylate analog binds exclusively in the synthetic site. Both structural data and tyrosine-dependent ATP hydrolysis enhanced by tRNA(Phe) provide evidence for a preferential posttransfer editing pathway in the phenylalanine-specific system.

About this StructureAbout this Structure

2AMC is a Protein complex structure of sequences from Thermus thermophilus with , and as ligands. Active as Phenylalanine--tRNA ligase, with EC number 6.1.1.20 Full crystallographic information is available from OCA.

ReferenceReference

Structural basis for discrimination of L-phenylalanine from L-tyrosine by phenylalanyl-tRNA synthetase., Kotik-Kogan O, Moor N, Tworowski D, Safro M, Structure. 2005 Dec;13(12):1799-807. PMID:16338408

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OCA

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-[[Image:2amc.gif|left|200px]]<br /><applet load="2amc" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:2amc.gif|left|200px]]<br /><applet load="2amc" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="2amc, resolution 2.70&Aring;" />
 '''Crystal structure of Phenylalanyl-tRNA synthetase complexed with L-tyrosine'''<br />
 ==Overview==
-Aminoacyl-tRNA synthetases (aaRSs) exert control over the faithful, transfer of amino acids onto cognate tRNAs. Since chemical structures of, various amino acids closely resemble each other, it is difficult to, discriminate between them. Editing activity has been evolved by certain, aaRSs to resolve the problem. In this study, we determined the crystal, structures of complexes of T. thermophilus phenylalanyl-tRNA synthetase, (PheRS) with L-tyrosine, p-chloro-phenylalanine, and a nonhydrolyzable, tyrosyl-adenylate analog. The structures demonstrate plasticity of the, synthetic site capable of binding substrates larger than phenylalanine and, provide a structural basis for the proofreading mechanism. The editing, site is localized at the B3/B4 interface, 35 A from the synthetic site., Glubeta334 plays a crucial role in the specific recognition of the Tyr, moiety in the editing site. The tyrosyl-adenylate analog binds exclusively, in the synthetic site. Both structural data and tyrosine-dependent ATP, hydrolysis enhanced by tRNA(Phe) provide evidence for a preferential, posttransfer editing pathway in the phenylalanine-specific system.
+Aminoacyl-tRNA synthetases (aaRSs) exert control over the faithful transfer of amino acids onto cognate tRNAs. Since chemical structures of various amino acids closely resemble each other, it is difficult to discriminate between them. Editing activity has been evolved by certain aaRSs to resolve the problem. In this study, we determined the crystal structures of complexes of T. thermophilus phenylalanyl-tRNA synthetase (PheRS) with L-tyrosine, p-chloro-phenylalanine, and a nonhydrolyzable tyrosyl-adenylate analog. The structures demonstrate plasticity of the synthetic site capable of binding substrates larger than phenylalanine and provide a structural basis for the proofreading mechanism. The editing site is localized at the B3/B4 interface, 35 A from the synthetic site. Glubeta334 plays a crucial role in the specific recognition of the Tyr moiety in the editing site. The tyrosyl-adenylate analog binds exclusively in the synthetic site. Both structural data and tyrosine-dependent ATP hydrolysis enhanced by tRNA(Phe) provide evidence for a preferential posttransfer editing pathway in the phenylalanine-specific system.
 ==About this Structure==
-AMC is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Thermus_thermophilus Thermus thermophilus] with MG, SO4 and TYR as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Phenylalanine--tRNA_ligase Phenylalanine--tRNA ligase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.1.1.20 6.1.1.20] Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2AMC OCA].
+AMC is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Thermus_thermophilus Thermus thermophilus] with <scene name='pdbligand=MG:'>MG</scene>, <scene name='pdbligand=SO4:'>SO4</scene> and <scene name='pdbligand=TYR:'>TYR</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Phenylalanine--tRNA_ligase Phenylalanine--tRNA ligase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.1.1.20 6.1.1.20] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2AMC OCA].
 ==Reference==
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 [[Category: protein-amino acid complex]]
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