FIG. 6.
Stem-loop IV in trans rescues a specific subset of CPDs with low processivity. (A) Telomerase was reconstituted with various telomerase RNA CPDs and mutants as indicated in the figure. +1, +7,+13, and +19 on the left indicate telomerase extension products from the d(GGGGTT)3 primer. For telomerase CPDs, the corresponding RNA region is indicated above each deletion or group of deletions. Each reconstituted telomerase was assayed for telomerase activity in the absence or presence of 500 pmol of distal stem-loop IV (nt 128 to 142). L.C., loading control for telomerase reactions.