X-ray structure of a soluble Rieske-type ferredoxin from Mus musculus.

TitleX-ray structure of a soluble Rieske-type ferredoxin from Mus musculus.
Publication TypeJournal Article
Year of Publication2008
AuthorsLevin EJ, Elsen NL, Seder KD, McCoy JG, Fox BG, Phillips GN
JournalActa Crystallogr D Biol Crystallogr
IssuePt 9
Date Published2008 Sep
KeywordsAnimals, Binding Sites, Cloning, Molecular, Crystallization, Crystallography, X-Ray, Ferredoxins, Humans, Mice, Models, Molecular, Phylogeny, Solubility, Static Electricity

The 2.07 A resolution X-ray crystal structure of a soluble Rieske-type ferredoxin from Mus musculus encoded by the gene Mm.266515 is reported. Although they are present as covalent domains in eukaryotic membrane oxidase complexes, soluble Rieske-type ferredoxins have not previously been observed in eukaryotes. The overall structure of the mouse Rieske-type ferredoxin is typical of this class of iron-sulfur proteins and consists of a larger partial beta-barrel domain and a smaller domain containing Cys57, His59, Cys80 and His83 that binds the [2Fe-2S] cluster. The S atoms of the cluster are hydrogen-bonded by six backbone amide N atoms in a pattern typical of membrane-bound high-potential eukaryotic respiratory Rieske ferredoxins. However, phylogenetic analysis suggested that the mouse Rieske-type ferredoxin was more closely related to bacterial Rieske-type ferredoxins. Correspondingly, the structure revealed an extended loop most similar to that seen in Rieske-type ferredoxin subunits of bacterial aromatic dioxygenases, including the positioning of an aromatic side chain (Tyr85) between this loop and the [2Fe-2S] cluster. The mouse Rieske-type ferredoxin was shown to be capable of accepting electrons from both eukaryotic and prokaryotic oxidoreductases, although it was unable to serve as an electron donor for a bacterial monooxygenase complex. The human homolog of mouse Rieske-type ferredoxin was also cloned and purified. It behaved identically to mouse Rieske-type ferredoxin in all biochemical characterizations but did not crystallize. Based on its high sequence identity, the structure of the human homolog is likely to be modeled well by the mouse Rieske-type ferredoxin structure.

Alternate JournalActa Crystallogr. D Biol. Crystallogr.
PubMed ID18703841
PubMed Central IDPMC2631127
Grant List5T15LM007359 / LM / NLM NIH HHS / United States
5T32HG002760 / HG / NHGRI NIH HHS / United States
U54 GM074901 / GM / NIGMS NIH HHS / United States