Role of a Cluster of Hydrophobic Residues Near the Fad Cofactor in Anabaena Pcc 7119 Ferredoxin-Nadp+ Reductase for Optimal Complex Formation and Electron Transfer to FerredoxinMarti-Nez-Julvez, M., Nogues, I., Faro, M., Hurley, J.K., Brodie, T.B., Mayoral, T., Sanz-Aparicio, J., Hermoso, J.A., Stankovich, M.T., Medina, M., Tollin, G., Gomez-Moreno, C.
(2001) J.Biol.Chem. 276: 27498
- PubMed: 11342548
- DOI: 10.1074/jbc.M102112200
- Primary Citation of Related Structures:  1QGZ, 1QH0
- PubMed Abstract:
- Probing the Determinants of Coenzyme Specificity in Ferredoxin-Nadp+ Reductase by Site-Directed Mutagenesis
Medina, M.,Luquita, A.,Tejero, J.,Hermoso, J.,Mayoral, T.,Sanz-Aparicio, J.,Grever, K.,Gomez-Moreno, C.
(2001) J.Biol.Chem. 276: 11902
- X-Ray Structure of the Ferredoxin:Nadp+ Reductase from the Cyanobacterium Anabanena Pcc 7119 at 1.8 Angstroms Resolution, and Crystallographic Studies of Nadp Binding at 2.25 Angstroms Resolution
Serre, L.,Vellieux, F.M.D.,Medina, M.,Gomez-Moreno, C.,Fontecilla, J.C.,Frey, M.
(1996) J.Mol.Biol. 263: 20
In the ferredoxin-NADP(+) reductase (FNR)/ferredoxin (Fd) system, an aromatic amino acid residue on the surface of Anabaena Fd, Phe-65, has been shown to be essential for the electron transfer (ET) reaction. We have investigated further the role of h ...
In the ferredoxin-NADP(+) reductase (FNR)/ferredoxin (Fd) system, an aromatic amino acid residue on the surface of Anabaena Fd, Phe-65, has been shown to be essential for the electron transfer (ET) reaction. We have investigated further the role of hydrophobic interactions in complex stabilization and ET between these proteins by replacing three hydrophobic residues, Leu-76, Leu-78, and Val-136, situated on the FNR surface in the vicinity of its FAD cofactor. Whereas neither the ability of FNR to accept electrons from NADPH nor its structure appears to be affected by the introduced mutations, different behaviors with Fd are observed. Thus, the ET interaction with Fd is almost completely lost upon introduction of negatively charged side chains. In contrast, only subtle changes are observed upon conservative replacement. Introduction of Ser residues produces relatively sizable alterations of the FAD redox potential, which can explain the modified behavior of these mutants. The introduction of bulky aromatic side chains appears to produce rearrangements of the side chains at the FNR/Fd interaction surface. Thus, subtle changes in the hydrophobic patch influence the rates of ET to and from Fd by altering the binding constants and the FAD redox potentials, indicating that these residues are especially important in the binding and orientation of Fd for efficient ET. These results are consistent with the structure reported for the Anabaena FNR.Fd complex.
Departamento de Bioquimica y Biologia Molecular y Celular, Facultad de Ciencias, Universidad de Zaragoza, 50009-Zaragoza, Spain.