title: Reactive Oxygen Species Production by Escherichia coli Respiratory Complex I.
abstract: Respiratory complex I couples the electron transfer exclusively from NADH to a quinone with the translocation of protons across the membrane. However, Escherichia coli adapts to imposed high cellular NADPH concentrations by selecting the mutations E183A(F) and E183G(F) that lead to a high catalytic efficiency of complex I with NADPH. Other mutations at position E183(F) resulting in an efficient NADPH oxidation were not selected. Here we show that the naturally occurring variants exhibit a remarkably low level of production of reactive oxygen species, a byproduct of NAD(P)H oxidation, that besides high catalytic efficiency might be favored by natural selection.
authors.affiliation: Institut für Biochemie, Albert-Ludwigs-Universität, 79104 Freiburg, Germany.
authors.forename: Klaudia
authors.initials: K
authors.lastname: Frick
authors.affiliation: Institut für Biochemie, Albert-Ludwigs-Universität, 79104 Freiburg, Germany.
authors.forename: Marius
authors.initials: M
authors.lastname: Schulte
authors.affiliation: Institut für Biochemie, Albert-Ludwigs-Universität, 79104 Freiburg, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Friedrich
mesh_terms: D055162:Biocatalysis; D042967:Electron Transport Complex I / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D009249:NADP / Q000378:metabolism; D010084:Oxidation-Reduction; D017382:Reactive Oxygen Species / Q000378:metabolism*
chemical_list: D029968:Escherichia coli Proteins; D017382:Reactive Oxygen Species; D009249:NADP; D042967:Electron Transport Complex I