1rfs
RIESKE SOLUBLE FRAGMENT FROM SPINACHRIESKE SOLUBLE FRAGMENT FROM SPINACH
Structural highlights
Function[UCRIA_SPIOL] Component of the cytochrome b6-f complex, which mediates electron transfer between photosystem II (PSII) and photosystem I (PSI), cyclic electron flow around PSI, and state transitions (By similarity). Evolutionary Conservation![]() Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedBACKGROUND: 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. 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[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References |
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