Asp-193 and Glu-218 of subunit II are involved in the Mn2+-binding of Paracoccus denitrificans cytochrome c oxidase.
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.
Witt
H
H
Institute of Biochemistry/Molecular Genetics, University of Frankfurt, Biozentrum, Germany.
Wittershagen
A
A
Bill
E
E
Kolbesen
B O
BO
Ludwig
B
B
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
D001224:Aspartic Acid; D018698:Glutamic Acid; D008345:Manganese; D003576:Electron Transport Complex IV