3oeq
Crystal structure of trimeric frataxin from the yeast Saccharomyces cerevisiae, with full length n-terminus
Structural highlights
FunctionFRDA_YEAST Promotes the biosynthesis of heme as well as the assembly and repair of iron-sulfur clusters by delivering Fe(2+) to proteins involved in these pathways. Plays a role in the protection against iron-catalyzed oxidative stress through its ability to catalyze the oxidation of Fe(2+) to Fe(3+). Can store large amounts of the metal in the form of a ferrihydrite mineral by oligomerization. May be involved in regulation of the mitochondrial electron transport chain.[1] [2] [3] [4] [5] [6] Publication Abstract from PubMedFrataxin is a mitochondrial protein with a central role in iron homeostasis. Defects in frataxin function lead to Friedreich's ataxia, a progressive neurodegenerative disease with childhood onset. The function of frataxin has been shown to be closely associated with its ability to form oligomeric species; however, the factors controlling oligomerization and the types of oligomers present in solution are a matter of debate. Using small-angle X-ray scattering, we found that Co(2+), glycerol, and a single amino acid substitution at the N-terminus, Y73A, facilitate oligomerization of yeast frataxin, resulting in a dynamic equilibrium between monomers, dimers, trimers, hexamers, and higher-order oligomers. Using X-ray crystallography, we found that Co(2+) binds inside the channel at the 3-fold axis of the trimer, which suggests that the metal has an oligomer-stabilizing role. The results reveal the types of oligomers present in solution and support our earlier suggestions that the trimer is the main building block of yeast frataxin oligomers. They also indicate that different mechanisms may control oligomer stability and oligomerization in vivo. Oligomerization Propensity and Flexibility of Yeast Frataxin Studied by X-ray Crystallography and Small-Angle X-ray Scattering.,Soderberg CA, Shkumatov AV, Rajan S, Gakh O, Svergun DI, Isaya G, Al-Karadaghi S J Mol Biol. 2011 Dec 16;414(5):783-97. Epub 2011 Oct 25. PMID:22051511[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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