Figure 4.
Folding dynamics of the telomerase RNA (TR) pseudoknot. (a) Using optical tweezers, the human telomerase pseudoknot was stretched to induce unfolding of the pseudoknot through base-pair shearing. Refolding of the pseudoknot was observed as the force is relaxed. Panel a adapted with permission from Reference 15. (b) Tetrahymena telomerase RNA pseudoknot folding during assembly into an active ribonucleoprotein (RNP) complex was monitored by single-molecule Förster resonance energy transfer (smFRET) (69). This result is consistent with models for an alternative RNA structure in the absence of telomerase proteins derived from biochemical and structural analyses (13, 19). Abbreviation: TERT, telomerase reverse transcriptase.