Fig. 4: Analyses of ROOLFirm variants.
a, Poorly resolved (disordered) regions are located in the cavities of ROOLFirm and ROOLEfa nanocages. These regions (D1, D2 in ROOLFirm and D, D′ in ROOLEfa) are coloured in low pass-filtered maps. The Gaussian filter with width 1.64 for the sharpened cryo-EM map is displayed at the following contours: 2.74σ for ROOLFirm, 2.49σ for ROOLEfa. b, Diagrams of ROOLFirm wild type (WT) and deletion mutants tested in this work, in which the disordered regions were removed. Each coloured box represents a helix scaled to length in the structure. c, Negative-stain analysis indicates that ROOLFirm deletion mutants without disordered regions can form nanocages similar to those formed by WT ROOLFirm. This experiment was performed once with two micrographs collected for each RNA. d, Design of ROOL–cargo RNA fusions. e, When fused to a Mango-III aptamer, pre-tRNA or primary microRNA (pri-miRNA) at the 3′ end, ROOLFirm forms stable nanocages with radially displayed cargoes demonstrated by negative-stain electron microscopy (micrographs shown) and corresponding 2D averages (examples of 12 classes are shown for each construct). This experiment was performed once with >70 micrographs collected for each RNA. For original and additional negative-stain micrographs, see Supplementary Fig. 1 and data deposited to Figshare35. Scale bars, 50 nm (c), 100 nm (e).
