Structure of Telomerase With Telomeric DNA

Cell. 2018 May 17;173(5):1179-1190.e13. doi: 10.1016/j.cell.2018.04.038.

Abstract

Telomerase is an RNA-protein complex (RNP) that extends telomeric DNA at the 3' ends of chromosomes using its telomerase reverse transcriptase (TERT) and integral template-containing telomerase RNA (TER). Its activity is a critical determinant of human health, affecting aging, cancer, and stem cell renewal. Lack of atomic models of telomerase, particularly one with DNA bound, has limited our mechanistic understanding of telomeric DNA repeat synthesis. We report the 4.8 Å resolution cryoelectron microscopy structure of active Tetrahymena telomerase bound to telomeric DNA. The catalytic core is an intricately interlocked structure of TERT and TER, including a previously structurally uncharacterized TERT domain that interacts with the TEN domain to physically enclose TER and regulate activity. This complete structure of a telomerase catalytic core and its interactions with telomeric DNA from the template to telomere-interacting p50-TEB complex provides unanticipated insights into telomerase assembly and catalytic cycle and a new paradigm for a reverse transcriptase RNP.

Keywords: CST; IFD; Penelope-like element; TPP1-POT1; group II intron; non-coding RNA; repeat addition processivity; replication protein A; retrotransposase; telomere.

Publication types

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

MeSH terms

  • Catalytic Domain
  • Cryoelectron Microscopy
  • DNA / chemistry
  • DNA / metabolism*
  • Humans
  • Models, Molecular
  • Nucleic Acid Conformation
  • Protein Binding
  • Protein Subunits / chemistry
  • Protein Subunits / metabolism
  • Tartrate-Resistant Acid Phosphatase / metabolism
  • Telomerase / chemistry
  • Telomerase / metabolism*
  • Telomere / chemistry
  • Telomere / metabolism*
  • Tetrahymena thermophila / enzymology
  • Tetrahymena thermophila / metabolism*

Substances

  • Protein Subunits
  • DNA
  • Telomerase
  • Tartrate-Resistant Acid Phosphatase