Fig 2: Cryo-EM analysis of ALECT2 fibrils.a. Representative cryo-EM micrographs showing single protofilament morphology (left) and double protofilament morphology (right). Scale bar: 20 nm. b. Representative 3D averages of ALECT2 fibrils. The left 3D class corresponds to the single-protofilament morphology, while the 3D classes on the right represent two distinct double-protofilament morphologies, double protofilament 1 and double protofilament 2 respectively. c. Single layer of ALECT2 fibril cryo-EM density map and its built-in atomic model. All 133 residues of the mature LECT2 protein are incorporated into the fibril structure, with their disulfide bonds retained (colored in yellow) and Val40 in gray dotted square. Extra densities that are predicted to be non-proteinaceous are drawn in black. d. Sequence of LECT2: scheme of the secondary structure elements of the single protofilament morphology. β-strands are numbered and marked with green arrows.