title: Structure of frataxin iron cores: an X-ray absorption spectroscopic study.
abstract: X-ray absorption spectroscopy at the iron K-edge indicates that the iron cores of human and yeast frataxin polymers assembled in vitro are identical to each other and are similar but not identical to ferritin cores. Both frataxin polymers contain ferrihydrite, a biomineral composed of ferric oxide/hydroxide octahedra. The ferrihydrite in frataxin is less ordered than iron cores of horse spleen ferritin, having fewer face-sharing Fe-Fe interactions but similar double corner-sharing interactions. The extended X-ray absorption fine structure (EXAFS) analysis agrees with previous electron microscopy data showing that frataxin cores are composed of very small ferrihydrite crystallites.
authors.affiliation: Department of Anatomy and Cell Biology, University of Saskatchewan, Saskatoon, Canada S7N 5E5. h.nichol@usask.ca
authors.forename: Helen
authors.initials: H
authors.lastname: Nichol
authors.forename: Oleksandr
authors.initials: O
authors.lastname: Gakh
authors.forename: Heather A
authors.initials: HA
authors.lastname: O'Neill
authors.forename: Ingrid J
authors.initials: IJ
authors.lastname: Pickering
authors.forename: Grazia
authors.initials: G
authors.lastname: Isaya
authors.forename: Graham N
authors.initials: GN
authors.lastname: George
mesh_terms: D000818:Animals; D005293:Ferritins / Q000737:chemistry; D006736:Horses; D006801:Humans; D007501:Iron / Q000737:chemistry / Q000378:metabolism; D033862:Iron-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism; D015394:Molecular Structure; D011994:Recombinant Proteins / Q000737:chemistry; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism; D013045:Species Specificity; D013057:Spectrum Analysis; D014965:X-Rays; D000096923:Frataxin
chemical_list: D005293:Ferritins; D007501:Iron; D033862:Iron-Binding Proteins; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D000096923:Frataxin