5NA4
NADH:quinone oxidoreductase (NDH-II) from Staphylococcus aureus - E172S mutant
Summary for 5NA4
| Entry DOI | 10.2210/pdb5na4/pdb |
| Related | 5NA1 |
| Descriptor | NADH dehydrogenase-like protein SAOUHSC_00878, FLAVIN-ADENINE DINUCLEOTIDE (3 entities in total) |
| Functional Keywords | oxidoreductase, nadh, respiratory chain, energetic metabolism |
| Biological source | Staphylococcus aureus |
| Total number of polymer chains | 1 |
| Total formula weight | 45731.65 |
| Authors | Brito, J.A.,Athayde, D.,Sousa, F.M.,Sena, F.V.,Pereira, M.M.,Archer, M. (deposition date: 2017-02-27, release date: 2018-01-10, Last modification date: 2024-01-17) |
| Primary citation | 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 Cited by 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: 28801048DOI: 10.1016/j.bbabio.2017.08.002 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.55 Å) |
Structure validation
Download full validation report
