1TKE

Crystal structure of the editing domain of threonyl-tRNA synthetase complexed with serine

Summary for 1TKE

• Entry DOI: 10.2210/pdb1tke/pdb
• Related: 1QF6 1TJE 1TKG 1TKY
• Descriptor: Threonyl-tRNA synthetase, SERINE (3 entities in total)
• Functional Keywords: ligase
• Biological source: Escherichia coli
• Cellular location: Cytoplasm: P0A8M3
• Total number of polymer chains: 1
• Total formula weight: 25571.02

Authors

Dock-Bregeon, A.C.,Rees, B.,Torres-Larios, A.,Bey, G.,Caillet, J.,Moras, D. (deposition date: 2004-06-08, release date: 2004-11-30, Last modification date: 2023-08-23)

Primary citation

Dock-Bregeon, A.C.,Rees, B.,Torres-Larios, A.,Bey, G.,Caillet, J.,Moras, D.
Achieving Error-Free Translation; The Mechanism of Proofreading of Threonyl-tRNA Synthetase at Atomic Resolution.
Mol.Cell, 16:375-386, 2004

PubMed Abstract: The fidelity of aminoacylation of tRNA(Thr) by the threonyl-tRNA synthetase (ThrRS) requires the discrimination of the cognate substrate threonine from the noncognate serine. Misacylation by serine is corrected in a proofreading or editing step. An editing site has been located 39 A away from the aminoacylation site. We report the crystal structures of this editing domain in its apo form and in complex with the serine product, and with two nonhydrolyzable analogs of potential substrates: the terminal tRNA adenosine charged with serine, and seryl adenylate. The structures show how serine is recognized, and threonine rejected, and provide the structural basis for the editing mechanism, a water-mediated hydrolysis of the mischarged tRNA. When the adenylate analog binds in the editing site, a phosphate oxygen takes the place of one of the catalytic water molecules, thereby blocking the reaction. This rules out a correction mechanism that would occur before the binding of the amino acid on the tRNA.

PubMed: 15525511
DOI: 10.1016/j.molcel.2004.10.002

Experimental method

X-RAY DIFFRACTION (1.46 Å)