title: Asp-193 and Glu-218 of subunit II are involved in the Mn2+-binding of Paracoccus denitrificans cytochrome c oxidase.
abstract: Cytochrome c oxidase contains a binding site for a non-redox-active metal at the interface of subunits I and II, usually a magnesium ion. In Paracoccus denitrificans oxidase, typically 20% may be replaced by manganese, using standard growth media. Site-directed mutants were constructed in subunit II (D193N and E218Q), and the isolated enzymes analyzed by total-reflection X-ray fluorescence spectrometry and EPR. Both mutants show a strong reduction of the manganese stoichiometry and a diminished electron transfer activity, demonstrating that D193 and E218 are involved in the binding of a manganese/magnesium ion in this site.
authors.affiliation: Institute of Biochemistry/Molecular Genetics, University of Frankfurt, Biozentrum, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Witt
authors.forename: A
authors.initials: A
authors.lastname: Wittershagen
authors.forename: E
authors.initials: E
authors.lastname: Bill
authors.forename: B O
authors.initials: BO
authors.lastname: Kolbesen
authors.forename: B
authors.initials: B
authors.lastname: Ludwig
mesh_terms: D000595:Amino Acid Sequence; D001224:Aspartic Acid / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D004578:Electron Spin Resonance Spectroscopy; D003576:Electron Transport Complex IV / Q000235:genetics / Q000378:metabolism*; D018698:Glutamic Acid / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D008345:Manganese / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D010231:Paracoccus denitrificans / Q000201:enzymology* / Q000235:genetics; D011485:Protein Binding / Q000235:genetics
chemical_list: D001224:Aspartic Acid; D018698:Glutamic Acid; D008345:Manganese; D003576:Electron Transport Complex IV