Interaction of cytochrome c with cytochrome c oxidase: an NMR study on two soluble fragments derived from Paracoccus denitrificans.
The functional interactions between the various components of the respiratory chain are relatively short-lived, thus allowing high turnover numbers but at the same time complicating the structural analysis of the complexes. Chemical shift mapping by NMR spectroscopy is a useful tool to investigate such transient contacts, since it can monitor changes in the electron-shielding properties of a protein as the result of temporary contacts with a reaction partner. In this study, we investigated the molecular interaction between two components of the electron-transfer chain from Paracoccus denitrificans: the engineered, water-soluble fragment of cytochrome c(552) and the Cu(A) domain from the cytochrome c oxidase. Comparison of [(15)N,(1)H]-TROSY spectra of the [(15)N]-labeled cytochrome c(552) fragment in the absence and in the presence of the Cu(A) fragment showed chemical shift changes for the backbone amide groups of several, mostly uncharged residues located around the exposed heme edge in cytochrome c(552). The detected contact areas on the cytochrome c(552) surface were comparable under both fully reduced and fully oxidized conditions, suggesting that the respective chemical shift changes represent biologically relevant protein-protein interactions.
Wienk
Hans
H
Institute of Biophysical Chemistry, J.W. Goethe-University, Marie-Curie-Strasse 9, D-60439 Frankfurt am Main, Germany.
Maneg
Oliver
O
Lücke
Christian
C
Pristovsek
Primoz
P
Löhr
Frank
F
Ludwig
Bernd
B
Rüterjans
Heinz
H
D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D003574:Cytochrome c Group / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D004579:Electron Transport; D003576:Electron Transport Complex IV / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006418:Heme / Q000737:chemistry; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D010084:Oxidation-Reduction; D010231:Paracoccus denitrificans / Q000235:genetics / Q000378:metabolism; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011487:Protein Conformation; D015202:Protein Engineering; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012995:Solubility
D001426:Bacterial Proteins; D003574:Cytochrome c Group; D010446:Peptide Fragments; D011994:Recombinant Proteins; C083951:cytochrome c553; D006418:Heme; C022302:cytochrome C-552; D003576:Electron Transport Complex IV