1g59

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spinqualitylabelsall models 1g59, resolution 2.4Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

GLUTAMYL-TRNA SYNTHETASE COMPLEXED WITH TRNA(GLU).

Overview

Glutamyl-tRNA synthetases (GluRSs) are divided into two distinct types, with regard to the presence or absence of glutaminyl-tRNA synthetase, (GlnRS) in the genetic translation systems. In the original 19-synthetase, systems lacking GlnRS, the 'non-discriminating' GluRS glutamylates both, tRNAGlu and tRNAGln. In contrast, in the evolved 20-synthetase systems, with GlnRS, the 'discriminating' GluRS aminoacylates only tRNAGlu. Here we, report the 2.4 A resolution crystal structure of a 'discriminating', GluRS.tRNAGlu complex from Thermus thermophilus. The GluRS recognizes the, tRNAGlu anticodon bases via two alpha-helical domains, maintaining the, base stacking. We show that the discrimination between the Glu and Gln, anticodons (34YUC36 and 34YUG36, respectively) is achieved by a single, arginine residue (Arg 358). The mutation of Arg 358 to Gln resulted in a, GluRS that does not discriminate between the Glu and Gln anticodons. This, change mimics the reverse course of GluRS evolution from anticodon, 'non-dicsriminating' to 'discriminating'.

About this Structure

1G59 is a Single protein structure of sequence from Thermus thermophilus. Active as Glutamate--tRNA ligase, with EC number 6.1.1.17 Full crystallographic information is available from OCA.

Reference

Structural basis for anticodon recognition by discriminating glutamyl-tRNA synthetase., Sekine S, Nureki O, Shimada A, Vassylyev DG, Yokoyama S, Nat Struct Biol. 2001 Mar;8(3):203-6. PMID:11224561

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