FIGURE 6.

Target RNA methylation increases when the target RNAs extend beyond the guide:target duplex. D target RNAs of increasing length were incubated with in vitro assembled sR8 box C/D sRNP and the methylation of target nucleotides assessed. (A) Schematic presentation of sR8 D guide region base paired with target RNAs of increasing length. Target nucleotides base paired with the guide sequence are indicated by dots with target RNA nucleotides extending beyond the guide:target RNA duplex indicated by N. Target nucleotides are enclosed in squares. Target RNAs are designated at the side with 5′ and 3′ nucleotides extended beyond the guide:target RNA indicated in the parentheses with respect to the 12 target nucleotides (T) base paired to the guide sequence. (B) Incorporation of ³H–CH₃ into D target RNAs of increasing length. Levels of target nucleotide methylation are indicated as the percent of the 14 nt control WT D target RNA.