ジャーナル: J Mol Biol / 年: 2009 タイトル: Globular tetramers of beta(2)-microglobulin assemble into elaborate amyloid fibrils. 著者: Helen E White / Julie L Hodgkinson / Thomas R Jahn / Sara Cohen-Krausz / Walraj S Gosal / Shirley Müller / Elena V Orlova / Sheena E Radford / Helen R Saibil / 要旨: Amyloid fibrils are ordered polymers in which constituent polypeptides adopt a non-native fold. Despite their importance in degenerative human diseases, the overall structure of amyloid fibrils ...Amyloid fibrils are ordered polymers in which constituent polypeptides adopt a non-native fold. Despite their importance in degenerative human diseases, the overall structure of amyloid fibrils remains unknown. High-resolution studies of model peptide assemblies have identified residues forming cross-beta-strands and have revealed some details of local beta-strand packing. However, little is known about the assembly contacts that define the fibril architecture. Here we present a set of three-dimensional structures of amyloid fibrils formed from full-length beta(2)-microglobulin, a 99-residue protein involved in clinical amyloidosis. Our cryo-electron microscopy maps reveal a hierarchical fibril structure built from tetrameric units of globular density, with at least three different subunit interfaces in this homopolymeric assembly. These findings suggest a more complex superstructure for amyloid than hitherto suspected and prompt a re-evaluation of the defining features of the amyloid fold.
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モデル: Tecnai F20 / 画像提供: FEI Company
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想定した対称性 - らせんパラメータ - Δz: 52.5 Å 想定した対称性 - らせんパラメータ - ΔΦ: 7.01 ° アルゴリズム: OTHER / 解像度のタイプ: BY AUTHOR / 解像度: 25.0 Å / 解像度の算出法: FSC 0.5 CUT-OFF / ソフトウェア - 名称: SPIDER 詳細: Maps were calculated for each class as each class had a different pitch.