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spinqualitylabelsall models 1ile, resolution 2.5Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

ISOLEUCYL-TRNA SYNTHETASE

Overview

High-fidelity transfers of genetic information in the central dogma can be, achieved by a reaction called editing. The crystal structure of an enzyme, with editing activity in translation is presented here at 2.5 angstroms, resolution. The enzyme, isoleucyl-transfer RNA synthetase, activates not, only the cognate substrate L-isoleucine but also the minimally distinct, L-valine in the first, aminoacylation step. Then, in a second, "editing", step, the synthetase itself rapidly hydrolyzes only the valylated, products. For this two-step substrate selection, a "double-sieve", mechanism has already been proposed. The present crystal structures of the, synthetase in complexes with L-isoleucine and L-valine demonstrate that, the first sieve is on the aminoacylation domain containing the Rossmann, fold, whereas the second, editing sieve exists on a globular beta-barrel, domain that protrudes from the aminoacylation domain.

About this Structure

1ILE is a Single protein structure of sequence from Thermus thermophilus with ZN as ligand. Full crystallographic information is available from OCA.

Reference

Enzyme structure with two catalytic sites for double-sieve selection of substrate., Nureki O, Vassylyev DG, Tateno M, Shimada A, Nakama T, Fukai S, Konno M, Hendrickson TL, Schimmel P, Yokoyama S, Science. 1998 Apr 24;280(5363):578-82. PMID:9554847

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