Fig. 1: Cryo-EM structure of SOD1 fibril.

a Raw cryo-EM image of amyloid fibrils assembled from recombinant, full-length apo human SOD1 under reducing conditions. Enlarged section of a (right) showing a single protofilament intertwined into a left-handed helix, with a fibril full width of 12.3 ± 0.7 nm and a helical pitch of 144 ± 5 nm. The scale bar represents 50 nm. The helical pitch and fibril width were measured and expressed as the mean ± SD of values obtained in n = 8 biologically independent measurements. Source data are provided as a Source Data file. b Cross-sectional view of the 3D map of the SOD1 fibril showing a protofilament comprising the N-terminal part (left) and the C-terminal part (right), with an unstructured flexible region (bottom). Scale bars, 5 nm. c 3D map showing a single protofilament (in orchid) intertwined into a left-handed helix, with a fibril core width of ~11 nm and a half-helical pitch of 73.1 nm. d Enlarged section showing a side view of the density map. Close-up view of the density map in c showing that the subunit in protofilament stacks along the fibril axis with a helical rise of 4.82 Å. e Top view of the density map.