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Updated: Aug 5, 2026
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Biochemical and Structural Characterization of the Carbohydrate Transport Substrate-binding-protein SP0092
Published on: October 2, 2017
Structural studies of lysyl-tRNA synthetase: conformational changes induced by substrate binding
S Onesti1, G Desogus, A Brevet
1Biophysics Section, Blackett Laboratory, Imperial College, London SW7 2BZ, UK. s.onesti@ic.ac.uk
Biochemistry
|October 21, 2000
Summary
Lysyl-tRNA synthetase (LysS) undergoes significant conformational changes when binding the lysine substrate. These structural shifts involve active site reorganization, leading to a closed conformation crucial for aminoacylation.
Area of Science:
- Biochemistry
- Structural Biology
- Molecular Biology
Background:
- Lysyl-tRNA synthetase (LysS) is a key enzyme in protein synthesis, belonging to the class II aminoacyl-tRNA synthetases.
- It catalyzes the specific attachment of lysine to its cognate transfer RNA (tRNA(Lys)).
Purpose of the Study:
- To elucidate the structural basis of lysine recognition and binding by Escherichia coli LysS.
- To understand the conformational changes that occur upon substrate binding.
Main Methods:
- X-ray crystallography was used to determine the structure of E. coli LysS.
- Structures were solved for both the unliganded enzyme and a complex with the lysine substrate at 2.7 Å resolution.
Main Results:
- Major conformational changes were observed between the unliganded and lysine-bound forms of LysS.
- Lysine binding induces a network of hydrogen bonds, including interactions with Gly 216 and Arg 262.
- These interactions trigger reorganization of the active site, involving loop ordering, conformational changes in residues 393-409, and a 10-degree rotation of a 4-helix bundle domain.
Conclusions:
- Lysine binding leads to a significant "closing up" of the LysS active site.
- This conformational change is essential for the enzyme's catalytic function in aminoacylation.
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