The Tetrahymena telomerase p75-p45-p19 subcomplex is a unique CST complex

Nat Struct Mol Biol. 2015 Dec;22(12):1023-6. doi: 10.1038/nsmb.3126. Epub 2015 Nov 9.


Tetrahymena telomerase holoenzyme subunits p75, p45 and p19 form a subcomplex (7-4-1) peripheral to the catalytic core. We report structures of p45 and p19 and reveal them as the Stn1 and Ten1 subunits of the CST complex, which stimulates telomerase complementary-strand synthesis. 7-4-1 binds telomeric single-stranded DNA, and mutant p19 overexpression causes telomere 3'-overhang elongation. We propose that telomerase-tethered Tetrahymena CST coordinates telomere G-strand and C-strand synthesis.

Publication types

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

MeSH terms

  • Models, Molecular
  • Protein Conformation
  • Protein Multimerization*
  • Protein Subunits / metabolism*
  • Telomerase / metabolism*
  • Telomere / metabolism
  • Tetrahymena / enzymology*


  • Protein Subunits
  • Telomerase

Associated data

  • PDB/5DOF
  • PDB/5DOI
  • PDB/5DOK