1h3n
From Proteopedia
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==Overview== | ==Overview== | ||
| - | Leucyl-, isoleucyl- and valyl-tRNA synthetases are closely related large | + | Leucyl-, isoleucyl- and valyl-tRNA synthetases are closely related large monomeric class I synthetases. Each contains a homologous insertion domain of approximately 200 residues, which is thought to permit them to hydrolyse ('edit') cognate tRNA that has been mischarged with a chemically similar but non-cognate amino acid. We describe the first crystal structure of a leucyl-tRNA synthetase, from the hyperthermophile Thermus thermophilus, at 2.0 A resolution. The overall architecture is similar to that of isoleucyl-tRNA synthetase, except that the putative editing domain is inserted at a different position in the primary structure. This feature is unique to prokaryote-like leucyl-tRNA synthetases, as is the presence of a novel additional flexibly inserted domain. Comparison of native enzyme and complexes with leucine and a leucyl- adenylate analogue shows that binding of the adenosine moiety of leucyl-adenylate causes significant conformational changes in the active site required for amino acid activation and tight binding of the adenylate. These changes are propagated to more distant regions of the enzyme, leading to a significantly more ordered structure ready for the subsequent aminoacylation and/or editing steps. |
==About this Structure== | ==About this Structure== | ||
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[[Category: class i aminoacyl-trna synthetase]] | [[Category: class i aminoacyl-trna synthetase]] | ||
| - | ''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 12:57:09 2008'' |
Revision as of 10:57, 21 February 2008
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LEUCYL-TRNA SYNTHETASE FROM THERMUS THERMOPHILUS COMPLEXED WITH A SULPHAMOYL ANALOGUE OF LEUCYL-ADENYLATE
Overview
Leucyl-, isoleucyl- and valyl-tRNA synthetases are closely related large monomeric class I synthetases. Each contains a homologous insertion domain of approximately 200 residues, which is thought to permit them to hydrolyse ('edit') cognate tRNA that has been mischarged with a chemically similar but non-cognate amino acid. We describe the first crystal structure of a leucyl-tRNA synthetase, from the hyperthermophile Thermus thermophilus, at 2.0 A resolution. The overall architecture is similar to that of isoleucyl-tRNA synthetase, except that the putative editing domain is inserted at a different position in the primary structure. This feature is unique to prokaryote-like leucyl-tRNA synthetases, as is the presence of a novel additional flexibly inserted domain. Comparison of native enzyme and complexes with leucine and a leucyl- adenylate analogue shows that binding of the adenosine moiety of leucyl-adenylate causes significant conformational changes in the active site required for amino acid activation and tight binding of the adenylate. These changes are propagated to more distant regions of the enzyme, leading to a significantly more ordered structure ready for the subsequent aminoacylation and/or editing steps.
About this Structure
1H3N is a Single protein structure of sequence from Thermus thermophilus with , and as ligands. Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
The 2 A crystal structure of leucyl-tRNA synthetase and its complex with a leucyl-adenylate analogue., Cusack S, Yaremchuk A, Tukalo M, EMBO J. 2000 May 15;19(10):2351-61. PMID:10811626[[Category: atp + l-leucine + trna (leu) -> amp + ppi + l-leucyl-trna(leu)]]
Page seeded by OCA on Thu Feb 21 12:57:09 2008
