FIG. 1.

Sequence and structure of engineered human U24 snoRNA (hU24). (A) Terminal C and D and internal C′ and D′ box sequences are in bold letters (enclosed) and folded to form the box C/D and C′/D′ motifs, respectively. Human D and D′ guide regions were replaced with the indicated sequences complementary to yeast 18S rRNA to target methylation of novel nucleotides A534 and U547, respectively, designated by asterisks. (B) Schematic presentation of engineered human U24 snoRNA. Box C, D, C′, and D′ sequences are indicated as boxes with the respective box C/D (K-turn) and C′/D′ (K-loop) motifs designated. Intermotif spacer regions are shown with the guide sequences complementary to 18S rRNA in bold lines and associated spacer regions in thin lines. The nucleotide lengths of the guide and associated spacer regions are indicated.