1h3e: Difference between revisions
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==Overview== | ==Overview== | ||
Bacterial tyrosyl-tRNA synthetases (TyrRS) possess a flexibly linked | Bacterial tyrosyl-tRNA synthetases (TyrRS) possess a flexibly linked C-terminal domain of approximately 80 residues, which has hitherto been disordered in crystal structures of the enzyme. We have determined the structure of Thermus thermophilus TyrRS at 2.0 A resolution in a crystal form in which the C-terminal domain is ordered, and confirm that the fold is similar to part of the C-terminal domain of ribosomal protein S4. We have also determined the structure at 2.9 A resolution of the complex of T.thermophilus TyrRS with cognate tRNA(tyr)(G Psi A). In this structure, the C-terminal domain binds between the characteristic long variable arm of the tRNA and the anti-codon stem, thus recognizing the unique shape of the tRNA. The anticodon bases have a novel conformation with A-36 stacked on G-34, and both G-34 and Psi-35 are base-specifically recognized. The tRNA binds across the two subunits of the dimeric enzyme and, remarkably, the mode of recognition of the class I TyrRS for its cognate tRNA resembles that of a class II synthetase in being from the major groove side of the acceptor stem. | ||
==About this Structure== | ==About this Structure== | ||
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[[Category: class i aminoacyl-trna synthetase: atp + l-tyrosine + trna(tyr) -> amp + ppi + l-tyrosyl-trna(tyr)]] | [[Category: class i aminoacyl-trna synthetase: atp + l-tyrosine + trna(tyr) -> amp + ppi + l-tyrosyl-trna(tyr)]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:56:58 2008'' | ||