Fig 2: Cycloheximide chase assay investigation of RPC5 protein stability.HEK293T cells were seeded, endogenous RPC5 was knocked down via siRNA and either the FL a, ?tWHD2 b, or ?C c, RPC5 constructs were transfected. After 24 h, cycloheximide was added in at a concentration of 300 µg/ml and cells lysed at the specified time points. RPC1, 2, 4 and 5 (as shown via HA-tag antibody) levels were probed by western blotting. Displayed images are representative of three independent experiments. Source data are provided as a Source Data file.

Fig 3: Structure of the RPC5 subunit C-terminal region.a Domain architecture of RPC5 C terminus. tWHD1 and tWHD2 are coloured in red and green shades, respectively. Regions are depicted according to their presence (black line) or absence (black dashed line) in the crystal structures. DM refers to RPC5 dimerization module. b Crystallographic model of RPC5-WHD1 (dark red), RPC5-WHD2 (light red) and the linker regions (grey) in ribbon cartoon. Inset shows detail of the electron density map. c Overall structure of RPC5-tWHD2 crystallographic packing in ribbon cartoon. RPC5-WHD3 and RPC5-WHD4 are shown in dark and light green, respectively, and the inset shows detail of the electron density map. d Fitting of RPC5-tWHD1 (red, inset) into the SAXS experimental data (black). e Fitting of RPC5-tWHD2 in ‘closed’ (green, inset), ‘open’ (dashed green) and dimer (orange) conformations into the SAXS experimental data (black). f Docking of RPC5-tWHD1 (red) and RPC5-tWHD2 (green) into the ab initio SAXS envelope generated from RPC5EXT SAXS data collection.