The N-terminus of mature human frataxin is intrinsically unfolded.
Frataxin is a highly conserved nuclear-encoded mitochondrial protein whose deficiency is the primary cause of Friedreich's ataxia, an autosomal recessive neurodegenerative disease. The frataxin structure comprises a well-characterized globular domain that is present in all species and is preceded in eukaryotes by a non-conserved N-terminal tail that contains the mitochondrial import signal. Little is known about the structure and dynamic properties of the N-terminal tail. Here, we show that this region is flexible and intrinsically unfolded in human frataxin. It does not alter the iron-binding or self-aggregation properties of the globular domain. It is therefore very unlikely that this region could be important for the conserved functions of the protein.
Prischi
Filippo
F
Dipartimento di Biologia Molecolare, University of Siena, Siena, Italy.
Giannini
Clelia
C
Adinolfi
Salvatore
S
Pastore
Annalisa
A
D000595:Amino Acid Sequence; D006801:Humans; D033862:Iron-Binding Proteins / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D017510:Protein Folding; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D000096923:Frataxin
D033862:Iron-Binding Proteins; D000096923:Frataxin