1rfs: Difference between revisions
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==Overview== | ==Overview== | ||
BACKGROUND: The cytochrome b6f complex functions in oxygenic | BACKGROUND: The cytochrome b6f complex functions in oxygenic photosynthesis as an integral membrane protein complex that mediates coupled electron transfer and proton translocation. The Rieske [2Fe-2S] protein subunit of the complex functions at the electropositive (p) membrane interface as the electron acceptor for plastoquinol and donor for the cytochrome f subunit, and may have a dynamic role in catalyzing electron and proton transfer at the membrane interface. There are significant structure/function similarities to the cytochrome bc1 complex of the respiratory chain. RESULTS: The 1.83 A crystal structure of a 139-residue C-terminal fragment of the Rieske [2Fe-2S] protein, derived from the cytochrome b6f complex of spinach chloroplasts, has been solved by multiwavelength anomalous diffraction. The structure of the fragment comprises two domains: a small 'cluster-binding' subdomain and a large subdomain. The [2Fe-2S] cluster-binding subdomains of the chloroplast and mitochondrial Rieske proteins are virtually identical, whereas the large subdomains are strikingly different despite a common folding topology. A structure-based sequence alignment of the b6f and bc1 groups of Rieske soluble domains is presented. CONCLUSIONS: The segregation of structural conservation and divergence in the cluster-binding and large subdomains of the Rieske protein correlates with the overall relatedness of the cytochrome b6f and bc1 complexes, in which redox domains in the aqueous p phase are dissimilar and those within the membrane are similar. Distinct sequences and surface charge distributions among Rieske large subdomains may provide a signature for interaction with the p-side oxidant protein and for the pH of the intraorganelle compartment. | ||
==About this Structure== | ==About this Structure== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Spinacia oleracea]] | [[Category: Spinacia oleracea]] | ||
[[Category: Carrell, C | [[Category: Carrell, C J.]] | ||
[[Category: Cramer, W | [[Category: Cramer, W A.]] | ||
[[Category: Smith, J | [[Category: Smith, J L.]] | ||
[[Category: Zhang, H.]] | [[Category: Zhang, H.]] | ||
[[Category: FES]] | [[Category: FES]] | ||
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[[Category: iron-sulfur protein]] | [[Category: iron-sulfur protein]] | ||
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Revision as of 15:50, 21 February 2008
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RIESKE SOLUBLE FRAGMENT FROM SPINACH
OverviewOverview
BACKGROUND: The cytochrome b6f complex functions in oxygenic photosynthesis as an integral membrane protein complex that mediates coupled electron transfer and proton translocation. The Rieske [2Fe-2S] protein subunit of the complex functions at the electropositive (p) membrane interface as the electron acceptor for plastoquinol and donor for the cytochrome f subunit, and may have a dynamic role in catalyzing electron and proton transfer at the membrane interface. There are significant structure/function similarities to the cytochrome bc1 complex of the respiratory chain. RESULTS: The 1.83 A crystal structure of a 139-residue C-terminal fragment of the Rieske [2Fe-2S] protein, derived from the cytochrome b6f complex of spinach chloroplasts, has been solved by multiwavelength anomalous diffraction. The structure of the fragment comprises two domains: a small 'cluster-binding' subdomain and a large subdomain. The [2Fe-2S] cluster-binding subdomains of the chloroplast and mitochondrial Rieske proteins are virtually identical, whereas the large subdomains are strikingly different despite a common folding topology. A structure-based sequence alignment of the b6f and bc1 groups of Rieske soluble domains is presented. CONCLUSIONS: The segregation of structural conservation and divergence in the cluster-binding and large subdomains of the Rieske protein correlates with the overall relatedness of the cytochrome b6f and bc1 complexes, in which redox domains in the aqueous p phase are dissimilar and those within the membrane are similar. Distinct sequences and surface charge distributions among Rieske large subdomains may provide a signature for interaction with the p-side oxidant protein and for the pH of the intraorganelle compartment.
About this StructureAbout this Structure
1RFS is a Single protein structure of sequence from Spinacia oleracea with as ligand. Known structural/functional Site: . Full crystallographic information is available from OCA.
ReferenceReference
Biological identity and diversity in photosynthesis and respiration: structure of the lumen-side domain of the chloroplast Rieske protein., Carrell CJ, Zhang H, Cramer WA, Smith JL, Structure. 1997 Dec 15;5(12):1613-25. PMID:9438861
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