Coordinated DNA dynamics during the human telomerase catalytic cycle

Nat Commun. 2014 Jun 13:5:4146. doi: 10.1038/ncomms5146.


The human telomerase reverse transcriptase (hTERT) utilizes a template within the integral RNA subunit (hTR) to direct extension of telomeres. Telomerase exhibits repeat addition processivity (RAP) and must therefore translocate the nascent DNA product into a new RNA:DNA hybrid register to prime each round of telomere repeat synthesis. Here, we use single-molecule FRET and nuclease protection assays to monitor telomere DNA structure and dynamics during the telomerase catalytic cycle. DNA translocation during RAP proceeds through a previously uncharacterized kinetic substep during which the 3'-end of the DNA substrate base pairs downstream within the hTR template. The rate constant for DNA primer realignment reveals this step is not rate limiting for RAP, suggesting a second slow conformational change repositions the RNA:DNA hybrid into the telomerase active site and drives the extrusion of the 5'-end of the DNA primer out of the enzyme complex.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Biocatalysis
  • Catalytic Domain
  • DNA / genetics*
  • DNA / metabolism
  • DNA Primers / genetics
  • DNA Primers / metabolism
  • Humans
  • RNA / genetics
  • RNA / metabolism
  • Telomerase / chemistry
  • Telomerase / genetics
  • Telomerase / metabolism*
  • Telomere / genetics
  • Telomere / metabolism
  • Transcription, Genetic


  • DNA Primers
  • telomerase RNA
  • RNA
  • DNA
  • TERT protein, human
  • Telomerase