4AQ7: Ternary Complex Of E. Coli Leucyl-Trna Synthetase, Trna(Leu) And Leucyl-Adenylate Analogue In The Aminoacylation Conformation

Citation:
Abstract
Leucyl-tRNA synthetase (LeuRS) produces error-free leucyl-tRNA(Leu) by coordinating translocation of the 3' end of (mis-)charged tRNAs from its synthetic site to a separate proofreading site for editing. Here we report cocrystal structures of the Escherichia coli LeuRS-tRNA(Leu) complex in the aminoacylation or editing conformations, showing that translocation involves correlated rotations of four flexibly linked LeuRS domains. This pivots the tRNA to guide its charged 3' end from the closed aminoacylation state to the editing site. The editing domain unexpectedly stabilizes the tRNA during aminoacylation, and a large rotation of the leucine-specific domain positions the conserved KMSKS loop to bind the 3' end of the tRNA, promoting catalysis. Our results give new insight into the structural dynamics of a molecular machine that is essential for accurate protein synthesis.
PDB ID: 4AQ7Download
MMDB ID: 100497
PDB Deposition Date: 2012/4/13
Updated in MMDB: 2012/11
Experimental Method:
x-ray diffraction
Resolution: 2.5  Å
Source Organism:
Escherichia coli K-12
Similar Structures:
Biological Unit for 4AQ7: dimeric; determined by author and by software (PISA)
Molecular Components in 4AQ7
Label Count Molecule
Protein (1 molecule)
1
Leucine--trna Ligase(Gene symbol: leuS)
Molecule annotation
Nucleotide(1 molecule)
1
E. Coli Trnaleu UAA Isoacceptor
Molecule annotation
Chemicals (3 molecules)
1
1
2
1
3
1
* Click molecule labels to explore molecular sequence information.

Citing MMDB
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