1gax

Publication Abstract from PubMed

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.

Structural 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 DG, Yokoyama S Cell. 2000 Nov 22;103(5):793-803. PMID:11114335^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.