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.
Dipartimento di Biologia Molecolare, University of Siena, Siena, Italy.
Filippo
F
Prischi
Clelia
C
Giannini
Salvatore
S
Adinolfi
Annalisa
A
Pastore
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