<p>The double-stranded RNA-binding domain (dsRBD), which is found in a variety of proteins, shares a common structure with the N-terminal domain of ribosomal protein S5, namely an alpha-beta(3)-alpha structure that folds into two layers, alpha/beta [<cite idref="PUB00018152"/>]. The dsRBD is found in a variety of functionally distinct proteins, including Drosophila staufen proteins (five copies of motif), dsRNA-dependent protein kinase pkr, and RNase III. Ribosomal protein S5 functions in the small ribosomal subunit, and in <taxon tax_id="562">Escherichia coli</taxon> has been shown to be important in the assembly and function of the 30S subunit. </p>