Structural and Redox Plasticity in the Heterodimeric Periplasmic Nitrate ReductaseArnoux, P., Sabaty, M., Alric, J., Frangioni, B., Guigliarelli, B., Adriano, J.-M., Pignol, D.
(2003) Nat.Struct.Mol.Biol. 10: 928
- PubMed: 14528294
- DOI: 10.1038/nsb994
- PubMed Abstract:
- The 1.25 A Resolution Structure of the Diheme Napb Subunit of Soluble Nitrate Reductase Reveals a Novel Cytochrome C Fold with a Stacked Heme Arrangement
Brige, A.,Leys, D.,Meyer, T.E.,Cusanovich, M.A.,Van Beeumen, J.J.
(2002) Biochemistry 41: 4827
- Crystal Structure of the First Dissimilatory Nitrate Reductase (Nap) at 1.9 A Solved by MAD Methods
Dias, J.M.,Than, M.,Humm, A.,Huber, R.,Bourenkov, G.,Bartunik, H.,Bursakov, S.,Calvete, J.,Caldeira, J.,Carneiro, C.,Moura, J.,Moura, I.,Romao, M.J.
(1999) Structure 7: 65
The structure of the respiratory nitrate reductase (NapAB) from Rhodobacter sphaeroides, the periplasmic heterodimeric enzyme responsible for the first step in the denitrification process, has been determined at a resolution of 3.2 A. The di-heme ele ...
The structure of the respiratory nitrate reductase (NapAB) from Rhodobacter sphaeroides, the periplasmic heterodimeric enzyme responsible for the first step in the denitrification process, has been determined at a resolution of 3.2 A. The di-heme electron transfer small subunit NapB binds to the large subunit with heme II in close proximity to the [4Fe-4S] cluster of NapA. A total of 57 residues at the N- and C-terminal extremities of NapB adopt an extended conformation, embracing the NapA subunit and largely contributing to the total area of 5,900 A(2) buried in the complex. Complex formation was studied further by measuring the variation of the redox potentials of all the cofactors upon binding. The marked effects observed are interpreted in light of the three-dimensional structure and depict a plasticity that contributes to an efficient electron transfer in the complex from the heme I of NapB to the molybdenum catalytic site of NapA.
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