2PVO
Crystal srtucture of the ternary complex between thioredoxin f, ferredoxin, and ferredoxin: thioredoxin reductase
Summary for 2PVO
Entry DOI | 10.2210/pdb2pvo/pdb |
Related | 2PU9 2PUK 2PUO 2PVD 2PVG |
Descriptor | Ferredoxin-thioredoxin reductase, catalytic chain, Ferredoxin-thioredoxin reductase, variable chain, Thioredoxin F-type, chloroplast, ... (7 entities in total) |
Functional Keywords | thioredoxin, ferredoxin. redox, iron-sulfur cluster, protein-protein complex, electron transport |
Biological source | Synechocystis sp. More |
Cellular location | Plastid, chloroplast: P09856 |
Total number of polymer chains | 4 |
Total formula weight | 44327.99 |
Authors | |
Primary citation | Dai, S.,Friemann, R.,Glauser, D.A.,Bourquin, F.,Manieri, W.,Schurmann, P.,Eklund, H. Structural snapshots along the reaction pathway of ferredoxin-thioredoxin reductase. Nature, 448:92-96, 2007 Cited by PubMed Abstract: Oxygen-evolving photosynthetic organisms regulate carbon metabolism through a light-dependent redox signalling pathway. Electrons are shuttled from photosystem I by means of ferredoxin (Fdx) to ferredoxin-thioredoxin reductase (FTR), which catalyses the two-electron-reduction of chloroplast thioredoxins (Trxs). These modify target enzyme activities by reduction, regulating carbon flow. FTR is unique in its use of a [4Fe-4S] cluster and a proximal disulphide bridge in the conversion of a light signal into a thiol signal. We determined the structures of FTR in both its one- and its two-electron-reduced intermediate states and of four complexes in the pathway, including the ternary Fdx-FTR-Trx complex. Here we show that, in the first complex (Fdx-FTR) of the pathway, the Fdx [2Fe-2S] cluster is positioned suitably for electron transfer to the FTR [4Fe-4S] centre. After the transfer of one electron, an intermediate is formed in which one sulphur atom of the FTR active site is free to attack a disulphide bridge in Trx and the other sulphur atom forms a fifth ligand for an iron atom in the FTR [4Fe-4S] centre--a unique structure in biology. Fdx then delivers a second electron that cleaves the FTR-Trx heterodisulphide bond, which occurs in the Fdx-FTR-Trx complex. In this structure, the redox centres of the three proteins are aligned to maximize the efficiency of electron transfer from the Fdx [2Fe-2S] cluster to the active-site disulphide of Trxs. These results provide a structural framework for understanding the mechanism of disulphide reduction by an iron-sulphur enzyme and describe previously unknown interaction networks for both Fdx and Trx (refs 4-6). PubMed: 17611542DOI: 10.1038/nature05937 PDB entries with the same primary citation |
Experimental method | X-RAY DIFFRACTION (3.4 Å) |
Structure validation
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