The structure of Acidithiobacillus ferrooxidans c(4)-cytochrome: a model for complex-induced electron transfer tuning.
The study of electron transfer between the copper protein rusticyanin (RCy) and the c(4)-cytochrome CYC(41) of the acidophilic bacterium Acidithiobacillus ferrooxidans has evidenced a remarkable decrease of RCy's redox potential upon complex formation. The structure of the CYC(41) obtained at 2.2 A resolution highlighted a specific glutamate residue (E121) involved in zinc binding as potentially playing a central role in this effect, required for the electron transfer to occur. EPR and stopped-flow experiments confirmed the strong inhibitory effect of divalent cations on CYC(41):RCy complex formation. A docking analysis of the CYC(41) and RCy structure allows us to propose a detailed model for the complex-induced tuning of electron transfer in agreement with our experimental data, which could be representative of other copper proteins involved in electron transfer.
Abergel
Chantal
C
Information Génomique et Structurale, UPR 2589, Institut de Biologie Structurale et Microbiologie, 31 Chemin Joseph Aiguier, 13402 20, Marseille cedex, France. chantal.abergel@igs.cnrs-mrs.fr
Nitschke
Wolfgang
W
Malarte
Guillaume
G
Bruschi
Mireille
M
Claverie
Jean-Michel
JM
Giudici-Orticoni
Marie-Thérèse
MT
D042763:Acidithiobacillus / Q000737:chemistry* / Q000378:metabolism; D000595:Amino Acid Sequence; D001400:Azurin / Q000031:analogs & derivatives* / Q000378:metabolism; D018360:Crystallography, X-Ray; D003574:Cytochrome c Group / Q000737:chemistry* / Q000378:metabolism; D004579:Electron Transport; D006418:Heme / Q000031:analogs & derivatives* / Q000378:metabolism; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D011485:Protein Binding; D017434:Protein Structure, Tertiary
D003574:Cytochrome c Group; C012543:rusticyanin; D001400:Azurin; C027728:heme a; C034186:cytochrome C4; D006418:Heme