The N-terminus of mature human frataxin is intrinsically unfolded

FEBS J. 2009 Nov;276(22):6669-76. doi: 10.1111/j.1742-4658.2009.07381.x. Epub 2009 Oct 16.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Humans
  • Iron-Binding Proteins / chemistry*
  • Magnetic Resonance Spectroscopy
  • Molecular Sequence Data
  • Protein Folding
  • Sequence Alignment
  • Sequence Homology, Amino Acid


  • Iron-Binding Proteins
  • frataxin