FIG. 2.

Telomerase activity reconstituted with telomerase RNA CPDs. (A) Telomerase activity assays were reconstituted with the telomerase RNAs indicated in the figure. +1, +7, +13, and +19 on the right indicate telomerase extension products from the d(GGGGTT)₃ primer. Quantified telomerase activity/processivity is shown below each lane expressed as % of wild-type (see methods). L.C., loading control added for all reactions. (B) Summary of the reconstituted telomerase activity levels of all 27 CPDs shown with the telomerase RNA secondary structure. The highlighted sequence indicates the RNA region deleted in each CPD. The CPD number is shown next to each highlighted RNA sequence from 5′ to 3′ along the RNA. The color indicates the relative level of telomerase activity. Red (50 to 100%) indicates wild-type activity. Orange (5 to 50%), purple (1 to 5%), and light blue (less than 1%) indicate activity less than that of the wild type. Gray indicates no activity, since no products at +1 were observed. Relevant telomerase RNA nucleotide positions are indicated on the figure. (C) Telomerase processivity quantification of selected CPDs. The intensity of each major band (+1, +7, +13, +19, and +25) from telomerase assay in panel A was quantified as described in the Materials and Methods and plotted for each repeat number. The processivity of each mutant is inversely related to the slope of the line.