Structural basis for the dual U4 and U4atac snRNA-binding specificity of spliceosomal protein hPrp31

Overall structure of the hPrp31^85–333–15.5K–U4atac complex. (A) Schematics of the 5′SL of U4 snRNA and U4atac snRNA. Binding of 15.5K (red) and hPrp31 (steel blue) is indicated schematically. (B) Overview of the hPrp31^85–333–15.5K–U4atac 5′SL complex. hPrp31^85–333, steel blue; 15.5K, red; U4atac RNA, green. The dashed line in hPrp31^85–333 indicates a disordered loop. Secondary structure elements are labeled. (C) The structure of the hPrp31^78–333–15.5K–U4 5′SL complex (PDB ID: 2OZB) shown in the same orientation. Coloring as in B, except U4 RNA is shown in gold.