Figure 6.

Mutating CS3 and CS4 decreases the incorporation of BclI-marked repeats onto telomeres and causes shifted template usage in vivo. PCR products were cloned and sequenced. Examples of telomere clone sequences from cells expressing P mutants. The TER RNA sequences are depicted in black, and the telomeric DNA sequences are colored blue for wild-type repeats, green for Bcl repeats added by the mutant telomerase (the phenotypically silent BclI-marker mutation in the RNA and the corresponding incorporated DNA sequences are boxed), and magenta for DNA sequence indicative of shifted template usage. Above the RNA sequence, the horizontal black bar denotes the maximal template sequence, containing the short repeated sequence at both ends (thicker black bars) thought to be required for realignment and synthesis of multiple telomeric repeats by wild-type telomerase; the red bars are the corresponding regions for the mutant Ters.