1g59

File:1g59.gif

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).

OverviewOverview

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 StructureAbout 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.

ReferenceReference

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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