Title: The structure of threonyl-tRNA synthetase-tRNA(Thr) complex enlightens its repressor activity and reveals an essential zinc ion in the active site. | Journal: Cell. 1999 Apr;97(3):371-81 | Authors: Sankaranarayanan R, Dock-Bregeon AC, Romby P, Caillet J, Springer M, Rees B, Ehresmann C, Ehresmann B, Moras D. | Abstract: E. coli threonyl-tRNA synthetase (ThrRS) is a class II enzyme that represses the translation of its own mRNA. We report the crystal structure at 2.9 A resolution of the complex between tRNA(Thr) and ThrRS, whose structural features reveal novel strategies for providing specificity in tRNA selection. These include an amino-terminal domain containing a novel protein fold that makes minor groove contacts with the tRNA acceptor stem. The enzyme induces a large deformation of the anticodon loop, resulting in an interaction between two adjacent anticodon bases, which accounts for their prominent role in tRNA identity and translational regulation. A zinc ion found in the active site is implicated in amino acid recognition/discrimination. | See full PubMed entry: http://www.ncbi.nlm.nih.gov/pubmed/10319817 |
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