1h85: Difference between revisions
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==Overview== | ==Overview== | ||
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 ... | 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. | ||
==About this Structure== | ==About this Structure== | ||
1H85 is a | 1H85 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Anabaena_sp. Anabaena sp.] with SO4 and FAD as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Ferredoxin--NADP(+)_reductase Ferredoxin--NADP(+) reductase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.18.1.2 1.18.1.2] Structure known Active Site: FAD. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1H85 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: oxidoreductase]] | [[Category: oxidoreductase]] | ||
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 13:56:03 2007'' | ||
