Fig. 2.

Recognition of double-stranded RNA (dsRNA) by the D1D2 core of human DDX3X. a Illustration of major protein–RNA interactions with one D1D2 core (MolA, ribbon diagram in cyan/palecyan, overlapped with a transparent molecular surface) and dsRNA (Strands 1 and 2 in blue/red, overlapped with composite omit 2mFo-DFc electron density map contoured at 1σ). MolB is not shown for clarity. b D1 recognizes both the 2ʹ-OH groups and phosphate backbone of nucleotide residues 11 and 12 in the central region of RNA Strand 1. c D2 mainly recognizes the phosphate backbone of nucleotide residues 20–22 near the 3ʹ end of the same RNA strand. d Schematic representation of protein–RNA interactions observed in the D1D2:dsRNA:D1D2 structure