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.
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
Chantal
C
Abergel
Wolfgang
W
Nitschke
Guillaume
G
Malarte
Mireille
M
Bruschi
Jean-Michel
JM
Claverie
Marie-Thérèse
MT
Giudici-Orticoni
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