InterPro domain: IPR017789

Frataxin is a mitochondrial protein, mutation of which leads to the disease Friedreich's ataxia [ 1 ]. Its orthologs are widely distributed in the bacteria, associated with the ISC system for iron-sulphur cluster assembly, and designated CyaY. Friedreich's ataxia is a progressive neurodegenerative disorder caused by loss of function mutations in the gene encoding frataxin (FRDA). Frataxin mRNA is predominantly expressed in tissues with a high metabolic rate (including liver, kidney, brown fat and heart). Mouse and yeast frataxin homologues contain a potential N-terminal mitochondrial targeting sequence, and human frataxin has been observed to co-localise with a mitochondrial protein. Furthermore, disruption of the yeast gene has been shown to result in mitochondrial dysfunction. Friedreich's ataxia is thus believed to be a mitochondrial disease caused by a mutation in the nuclear genome (specifically, expansion of an intronic GAA triplet repeat) [ 2 , 3 , 4 ].

1. Friedreich's ataxia protein: phylogenetic evidence for mitochondrial dysfunction. Trends Neurosci. 19, 465-8
2. Friedreich's ataxia: autosomal recessive disease caused by an intronic GAA triplet repeat expansion. Science 271, 1423-7
3. Clinical and genetic abnormalities in patients with Friedreich's ataxia. N. Engl. J. Med. 335, 1169-75
4. Studies of human, mouse and yeast homologues indicate a mitochondrial function for frataxin. Nat. Genet. 16, 345-51