The structure of threonyl-tRNA synthetase-tRNA(Thr) complex enlightens its repressor activity and reveals an essential zinc ion in the active site
Sankaranarayanan, R., Dock-Bregeon, A.C., Romby, P., Caillet, J., Springer, M., Rees, B., Ehresmann, C., Ehresmann, B., Moras, D.(1999) Cell 97: 371-381
- PubMed: 10319817 
- DOI: https://doi.org/10.1016/s0092-8674(00)80746-1
- Primary Citation of Related Structures:  
1QF6 - PubMed 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.
Organizational Affiliation: 
UPR 9004 Biologie Structurale, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP, Illkirch, France.