Download MendeleyStructural basis for double-sieve discrimination of L-valine from L-isoleucine and L-threonine by the complex of tRNA(Val) and valyl-tRNA synthetase.
Fukai, S., Nureki, O., Sekine, S., Shimada, A., Tao, J., Vassylyev, D.G., Yokoyama, S.(2000) Cell 103: 793-803
- PubMed: 11114335
- DOI: https://doi.org/10.1016/s0092-8674(00)00182-3
- Primary Citation of Related Structures:
1GAX - PubMed Abstract:
Valyl-tRNA synthetase (ValRS) strictly discriminates the cognate L-valine from the larger L-isoleucine and the isosteric L-threonine by the tRNA-dependent "double sieve" mechanism. In this study, we determined the 2.9 A crystal structure of a complex of Thermus thermophilus ValRS, tRNA(Val), and an analog of the Val-adenylate intermediate. The analog is bound in a pocket, where Pro(41) allows accommodation of the Val and Thr moieties but precludes the Ile moiety (the first sieve), on the aminoacylation domain. The editing domain, which hydrolyzes incorrectly synthesized Thr-tRNA(Val), is bound to the 3' adenosine of tRNA(Val). A contiguous pocket was found to accommodate the Thr moiety, but not the Val moiety (the second sieve). Furthermore, another Thr binding pocket for Thr-adenylate hydrolysis was suggested on the editing domain.
Organizational Affiliation:
Department of Biophysics and Biochemistry Graduate School of Science The University of Tokyo 7-3-1 Hongo Bunkyo-ku, 113-0033, Tokyo, Japan.
