614735.fig.005a
(a)
614735.fig.005b
(b)
Figure 5: Structures of archaeal box C/D sRNPs. (a) Top panel, two views of negatively stained EM reconstruction of S. solfataricus box C/D sRNP reconstituted with a natural sRNA (adapted from [16]). Crystal structures of the core proteins, L7Ae (blue), Nop5 (green), and fibrillarin (cyan), are docked into the volume. Bottom panel, schematic of the di-sRNP model. (b) Top panel, two views of the X-ray crystal structure of S. solfataricus box C/D sRNP reconstituted with a nonnatural sRNA, rendered in PyMol (PDB ID: 3PLA [17]). Core proteins are color-coded as in (a). sRNA is in yellow and the substrate RNA is in red. Bottom panel, schematic of the mono-sRNP model.