Figure 1.
Double-stranded RNA recognition by double-stranded RNA-binding motifs. (A) The double-stranded RNA-binding motif (dsRBM) of Xlrbpa2 bound to dsRNA (Ryter & Schultz, 1998). The α-helix 1 (in red), amino-terminal part of α-helix 2, and β1–β2 loop recognize non-sequence-specifically the shape of dsRNA. Backbones are coloured blue and light blue for two co-axially stacked duplexes. (B) The dsRBM of Rnt1p bound to the stem–loop closed by the AGNN tetraloop (backbone in yellow and bases in black; Wu et al, 2004). The α-helix 1, a key element for shape-specific recognition by dsRBMs, is highlighted in red. The dsRBM of Rnt1p has an additional carboxy-terminal α-helix 3 (in black), that modulates the conformation of α-helix 1 (Leulliot et al, 2004). Side chains involved in intermolecular interactions are shown.