3DEN

Structure of E. coli DHDPS mutant Y107W

3DEN の概要

• エントリーDOI: 10.2210/pdb3den/pdb
• 分子名称: Dihydrodipicolinate synthase, POTASSIUM ION, GLYCEROL, ... (5 entities in total)
• 機能のキーワード: dihydrodipicolinate synthase, monomer, quaternary structure, amino-acid biosynthesis, diaminopimelate biosynthesis, lyase, lysine biosynthesis, schiff base
• 由来する生物種: Escherichia coli K-12
• 細胞内の位置: Cytoplasm: P0A6L2
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 63549.47

構造登録者

Pearce, F.G.,Gerrard, J.A.,Perugini, M.A.,Jameson, G.B. (登録日: 2008-06-10, 公開日: 2008-11-25, 最終更新日: 2023-11-01)

主引用文献

Pearce, F.G.,Dobson, R.C.J.,Weber, A.,Lane, L.A.,McCammon, M.G.,Squire, M.A.,Perugini, M.A.,Jameson, G.B.,Robinson, C.V.,Gerrard, J.A.
Mutating the tight-dimer interface of dihydrodipicolinate synthase disrupts the enzyme quaternary structure: toward a monomeric enzyme
Biochemistry, 47:12108-12117, 2008

PubMed Abstract: Dihydrodipicolinate synthase (DHDPS) is a tetrameric enzyme that is the first enzyme unique to the ( S)-lysine biosynthetic pathway in plants and bacteria. Previous studies have looked at the important role of Tyr107, an amino acid residue located at the tight-dimer interface between two monomers, in participating in a catalytic triad of residues during catalysis. In this study, we examine the importance of this residue in determining the quaternary structure of the DHDPS enzyme. The Tyr107 residue was mutated to tryptophan, and structural, biophysical, and kinetic studies were carried out on the mutant enzyme. These revealed that while the solid-state structure of the mutant enzyme was largely unchanged, as judged by X-ray crystallography, it exists as a mixture of primarily monomer and tetramer in solution, as determined by analytical ultracentrifugation, size-exclusion chromatography, and mass spectrometry. The catalytic ability of the DHDPS enzyme was reduced by the mutation, which also allowed the adventitious binding of alpha-ketoglutarate to the active site. A reduction in the apparent melting temperature of the mutant enzyme was observed. Thus, the tetrameric quaternary structure of DHDPS is critical to controlling specificity, heat stability, and intrinsic activity.

PubMed: 18937497
DOI: 10.1021/bi801094t

実験手法

X-RAY DIFFRACTION (2.2 Å)