How does telomerase work?

Telomerase uses the 3′–OH of the G+T telomeric strand to prime synthesis of tandem TTGGGG repeats. The RNA component of telomerase has a sequence that pairs with the C+A-rich repeats. One of the protein subunits is a reverse transcriptase that uses the RNA as template to synthesis the G+T-rich sequence. -Telomerase positions itself by base pairing between the RNA template and the protruding single-stranded DNA primer.