ジャーナル: Structure / 年: 2015 タイトル: Amyloidogenesis of bacterial prionoid RepA-WH1 recapitulates dimer to monomer transitions of RepA in DNA replication initiation. 著者: Eva Torreira / María Moreno-Del Álamo / Maria Eugenia Fuentes-Perez / Cristina Fernández / Jaime Martín-Benito / Fernando Moreno-Herrero / Rafael Giraldo / Oscar Llorca / 要旨: Most available structures of amyloids correspond to peptide fragments that self-assemble in extended cross β sheets. However, structures in which a whole protein domain acts as building block of an ...Most available structures of amyloids correspond to peptide fragments that self-assemble in extended cross β sheets. However, structures in which a whole protein domain acts as building block of an amyloid fiber are scarce, in spite of their relevance to understand amyloidogenesis. Here, we use electron microscopy (EM) and atomic force microscopy (AFM) to analyze the structure of amyloid filaments assembled by RepA-WH1, a winged-helix domain from a DNA replication initiator in bacterial plasmids. RepA-WH1 functions as a cytotoxic bacterial prionoid that recapitulates features of mammalian amyloid proteinopathies. RepA are dimers that monomerize at the origin to initiate replication, and we find that RepA-WH1 reproduces this transition to form amyloids. RepA-WH1 assembles double helical filaments by lateral association of a single-stranded precursor built by monomers. Double filaments then associate in mature fibers. The intracellular and cytotoxic RepA-WH1 aggregates might reproduce the hierarchical assembly of human amyloidogenic proteins.
The particles were 2D-classified using CL2D implemented in Xmipp, and further processed using IHRSR. Note: Due to map resolution, the hand is arbitrary.
最終 再構成
想定した対称性 - らせんパラメータ - Δz: 12.5 Å 想定した対称性 - らせんパラメータ - ΔΦ: 81 ° 想定した対称性 - らせんパラメータ - 軸対称性: C1 (非対称) 解像度のタイプ: BY AUTHOR / 解像度: 29.0 Å / 解像度の算出法: OTHER