Multiple DNA Interactions Contribute to the Initiation of Telomerase Elongation

Research output: Contribution to journalArticle

Abstract

Telomerase maintains telomere length and chromosome integrity by adding short tandem repeats of single-stranded DNA to the 3' ends, via reverse transcription of a defined template region of its RNA subunit. To further understand the telomerase elongation mechanism, we studied the primer utilization and extension activity of the telomerase from the budding yeast Naumovozyma castellii (Saccharomyces castellii), which displays a processive nucleotide and repeat addition polymerization. For the efficient initiation of canonical elongation, telomerase required 4-nt primer 3' end complementarity to the template RNA. This DNA-RNA hybrid formation was highly important for the stabilization of an initiation-competent telomerase-DNA complex. Anchor site interactions with the DNA provided additional stabilization to the complex. Our studies indicate three additional separate interactions along the length of the DNA primer, each providing different and distinct contributions to the initiation event. A sequence-independent anchor site interaction acts immediately adjacent to the base-pairing 3' end, indicating a protein anchor site positioned very close to the catalytic site. Two additional anchor regions further 5' on the DNA provide sequence-specific contributions to the initiation of elongation. Remarkably, a non-telomeric sequence in the distal 25- to 32-nt region negatively influences the initiation of telomerase elongation, suggesting an anchor site with a regulatory role in the telomerase elongation decision.

Details

Authors
  • Ahu Karademir Andersson
  • Cecilia Gustafsson
  • Roopesh Krishnankutty
  • Marita Cohn
Organisations
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Biochemistry and Molecular Biology

Keywords

  • DNA-protein interaction, Naumovozyma castellii, Repeat addition processivity, Telomerase substrate specificity, Telomere
Original languageEnglish
Pages (from-to)2109-2123
Number of pages15
JournalJournal of Molecular Biology
Volume429
Issue number14
Publication statusPublished - 2017 Jul 7
Publication categoryResearch
Peer-reviewedYes