5NA4

NADH:quinone oxidoreductase (NDH-II) from Staphylococcus aureus - E172S mutant

5NA4 の概要

• エントリーDOI: 10.2210/pdb5na4/pdb
• 関連するPDBエントリー: 5NA1
• 分子名称: NADH dehydrogenase-like protein SAOUHSC_00878, FLAVIN-ADENINE DINUCLEOTIDE (3 entities in total)
• 機能のキーワード: oxidoreductase, nadh, respiratory chain, energetic metabolism
• 由来する生物種: Staphylococcus aureus
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 45731.65

構造登録者

Brito, J.A.,Athayde, D.,Sousa, F.M.,Sena, F.V.,Pereira, M.M.,Archer, M. (登録日: 2017-02-27, 公開日: 2018-01-10, 最終更新日: 2024-01-17)

主引用文献

Sousa, F.M.,Sena, F.V.,Batista, A.P.,Athayde, D.,Brito, J.A.,Archer, M.,Oliveira, A.S.F.,Soares, C.M.,Catarino, T.,Pereira, M.M.
The key role of glutamate 172 in the mechanism of type II NADH:quinone oxidoreductase of Staphylococcus aureus.
Biochim. Biophys. Acta, 1858:823-832, 2017

PubMed Abstract: Type II NADH:quinone oxidoreductases (NDH-2s) are membrane bound enzymes that deliver electrons to the respiratory chain by oxidation of NADH and reduction of quinones. In this way, these enzymes also contribute to the regeneration of NAD, allowing several metabolic pathways to proceed. As for the other members of the two-Dinucleotide Binding Domains Flavoprotein (tDBDF) superfamily, the enzymatic mechanism of NDH-2s is still little explored and elusive. In this work we addressed the role of the conserved glutamate 172 (E172) residue in the enzymatic mechanism of NDH-2 from Staphylococcus aureus. We aimed to test our earlier hypothesis that E172 plays a key role in proton transfer to allow the protonation of the quinone. For this we performed a complete biochemical characterization of the enzyme's variants E172A, E172Q and E172S. Our steady state kinetic measurements show a clear decrease in the overall reaction rate, and our substrate interaction studies indicate the binding of the two substrates is also affected by these mutations. Interestingly our fast kinetic results show quinone reduction is more affected than NADH oxidation. We have also determined the X-ray crystal structure of the E172S mutant (2.55Ǻ) and compared it with the structure of the wild type (2.32Ǻ). Together these results support our hypothesis for E172 being of central importance in the catalytic mechanism of NDH-2, which may be extended to other members of the tDBDF superfamily.

PubMed: 28801048
DOI: 10.1016/j.bbabio.2017.08.002

実験手法

X-RAY DIFFRACTION (2.55 Å)