FIGURE 7.

Extended target RNAs significantly enhance nucleotide methylation activity by increasing catalytic turnover. Short WT D (14 nt) and extended D target RNAs (21 nt) were incubated with in vitro assembled sR8 box C/D sRNP and nucleotide methylation assessed at three different molar ratios of D target RNA to sRNP. Upper panels indicate picomoles of short WT (circles) and extended (squares) D target RNAs methylated over 30-min incubation periods. Lower panels indicate sRNP turnover for short WT (circles) and extended (squares) D target RNAs calculated from the average picomoles of product produced per 30-min incubation period. Molar ratios of target RNA to sRNP are indicated at the top.