Promotes the biosynthesis of heme and assembly and repair of iron-sulfur clusters by delivering Fe(2+) to proteins involved in these pathways. May play a role in the protection against iron-catalyzed oxidative stress through its ability to catalyze the oxidation of Fe(2+) to Fe(3+); the oligomeric form but not the monomeric form has in vitro ferroxidase activity. May be able to store large amounts of iron in the form of a ferrihydrite mineral by oligomerization; however, the physiological relevance is unsure as reports are conflicting and the function has only been shown using heterologous overexpression systems. Modulates the RNA-binding activity of ACO1.
Specificity
Natural and recombinant Human Frataxin, mitochondrial
Subcellular Location
Cytoplasm Mitochondrion PubMed:18725397 reports localization exclusively in mitochondria.
Monomer (probable predominant form). Oligomer. Monomers and polymeric aggregates of >1 MDa have been isolated from mitochondria. A small fraction of heterologous overexpressed recombinant frataxin forms high-molecular wight aggregates that incoroprate iron. Interacts with LYRM4 AND HSPA9. Interacts with ACO1. Interacts with ISCU isoform 1 and isoform 2. Interacts with FECH; one iron-bound FXN monomer seems to interact with a FECH homodimer. Interacts with SDHA and SDHB. Interacts with ACO2; the interaction is dependent on citrate.