caa a22 4500 445325429 CHVBK 20180317142718.0 cr unu---uuuuu 170323e20110901xx s 000 0 eng 10.1007/s10858-011-9542-0 doi (NATIONALLICENCE)springer-10.1007/s10858-011-9542-0 Active site dynamics in NADH oxidase from Thermus thermophilus studied by NMR spin relaxation [Elektronische Daten] [Teresa Miletti, Patrick Farber, Anthony Mittermaier] We have characterized the backbone dynamics of NADH oxidase from Thermus thermophilus (NOX) using a recently-developed suite of NMR experiments designed to isolate exchange broadening, together with 15N R 1, R 1ρ , and {1H}-15N steady-state NOE relaxation measurements performed at 11.7 and 18.8 T. NOX is a 54kDa homodimeric enzyme that belongs to a family of structurally homologous flavin reductases and nitroreductases with many potential biotechnology applications. Prior studies have suggested that flexibility is involved in the catalytic mechanism of the enzyme. The active site residue W47 was previously identified as being particularly important, as its level of solvent exposure correlates with enzyme activity, and it was observed to undergo "gating” motions in computer simulations. The NMR data are consistent with these findings. Signals from W47 are dynamically broadened beyond detection and several other residues in the active site have significant R ex contributions to transverse relaxation rates. In addition, the backbone of S193, whose side chain hydroxyl proton hydrogen bonds directly with the FMN cofactor, exhibits extensive mobility on the ns-ps timescale. We hypothesize that these motions may facilitate structural rearrangements of the active site that allow NOX to accept both FMN and FAD as cofactors. Springer Science+Business Media B.V., 2011 Protein dynamics nationallicence NMR spin relaxation nationallicence NADH oxidase nationallicence Catalytic mechanism nationallicence Miletti Teresa Department of Chemistry, McGill University, H3A 2K6, Montreal, QC, Canada aut Farber Patrick Department of Chemistry, McGill University, H3A 2K6, Montreal, QC, Canada aut Mittermaier Anthony Department of Chemistry, McGill University, H3A 2K6, Montreal, QC, Canada aut Journal of Biomolecular NMR Springer Netherlands 51/1-2(2011-09-01), 71-82 0925-2738 51:1-2<71 2011 51 10858 https://doi.org/10.1007/s10858-011-9542-0 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10858-011-9542-0 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Miletti Teresa Department of Chemistry, McGill University, H3A 2K6, Montreal, QC, Canada aut NATIONALLICENCE 700 1- Farber Patrick Department of Chemistry, McGill University, H3A 2K6, Montreal, QC, Canada aut NATIONALLICENCE 700 1- Mittermaier Anthony Department of Chemistry, McGill University, H3A 2K6, Montreal, QC, Canada aut NATIONALLICENCE 773 0- Journal of Biomolecular NMR Springer Netherlands 51/1-2(2011-09-01), 71-82 0925-2738 51:1-2<71 2011 51 10858 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer