Fig. 2: Polymorphism in β2m-ΔN6 fibrils.
From: Disease-relevant β2-microglobulin variants share a common amyloid fold
a Representative cryoEM micrograph of β2m-ΔN6 fibrils (scale bar corresponds to 50 nm). Two independent experiments were performed, with similar results. b–d Cross sections through the 3D reconstructions of the three polymorphs found in the β2m-ΔN6 data: b ΔN6-1PFa, c ΔN6-2PFa and d ΔN6-2PFb. For each map, a sum of the reconstructed densities for six XY-slices is shown, corresponding to one ~4.8 Å repeat of the amyloid core of the fibril. e–g Surface representation of the same structures with relative distributions and final map resolutions annotated. h, Refined density at 3.0 Å resolution for the ΔN6-2PFa structure with its accompanying atomic model. Protofilament #1 is in yellow, and protofilament #2 is orange. The EM density is shown as a mesh, and the atomic model as a cartoon with the same colour, and sidechains coloured according to a CPK scheme. i The disulphide bond between residues 25 and 80 is present and well-resolved. j, k, as for h, i, but showing the 3.4 Å structure of ΔN6-2PFb and the accompanying atomic model, with protofilament #1 in light blue, and protofilament #2 in darker blue.
