Structural alignment and sequence comparison of domains in hStau and other double-stranded RNA (dsRNA)-binding proteins. (A) Structure of hStau and other proteins that contain double-stranded RNA-binding domains. Full-length dsRNA-binding domains are indicated by gray boxes, and short domains are indicated by white boxes. The numbers under the domains in hStau and Staufen correspond to the sequences listed in B. (B) Sequence homology between double-stranded RNA-binding domains of human Staufen and Drosophila Staufen (STAU). Top and Middle, alignment of the full-length domains. Bottom, alignment of the short domains. Identical residues are shaded; * symbols indicate the residues that are highly conserved in most of the double-stranded RNA-binding domains containing proteins (St. Johnston et al., 1992) (note that not all sequences are shown). Sequences used in the alignment are as follows: hStau-1, aa 59–79; hStau-2, aa 100–172; hStau-3, aa 202–275; hStau-4, aa 452–472; STAU-1, aa 308–380; STAU-2, aa 490–559; STAU-3, aa 575–647; STAU-4, aa 708–782; and STAU-5, aa 948-1020.