Cdc13 and telomerase bind through different mechanisms at the lagging- and leading-strand telomeres

Mol Cell. 2010 Jun 25;38(6):842-52. doi: 10.1016/j.molcel.2010.05.016.


Lagging-strand and leading-strand synthesis of chromosomes generates two structurally distinct ends at the telomeres. Based on sequence bias of yeast telomeres that contain a 250-300 bp array of C(1-3)A/ TG(1-3) repeats, we developed a method allowing us to distinguish which of the two daughter telomeres chromosome end-binding proteins bind to at the end of S phase. The single-stranded DNA-binding protein Cdc13 and the telomerase subunits Est1 and Est2 can bind to the two daughter telomeres, but only their binding to the leading-strand telomere depends on the Mre11/Rad50/Xrs2 (MRX) complex involved in both telomeric 5' nucleolytic resection and telomerase recruitment at short telomeres. Consistently, the MRX complex is mainly found to bind to the leading-strand telomere. Our results indicate that Cdc13 can bind to the telomeric template for lagging-strand replication. Since mre11-deficient strains have markedly short telomeres, telomere elongation by telomerase is likely to occur mainly at the leading-strand telomere.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Endodeoxyribonucleases / metabolism
  • Exodeoxyribonucleases / metabolism
  • Protein Binding
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae / ultrastructure
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Telomerase / metabolism*
  • Telomere / metabolism*
  • Telomere-Binding Proteins / metabolism*


  • Cdc13 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Telomere-Binding Proteins
  • EST1 protein, S cerevisiae
  • EST2 protein, S cerevisiae
  • Telomerase
  • Endodeoxyribonucleases
  • Exodeoxyribonucleases
  • MRE11 protein, S cerevisiae