@article{90931,
  keywords = {Animals, DNA, Single-Stranded, DNA, Kinetics, Protein Structure, Tertiary, cell cycle, Mutation, Escherichia coli, Protein Binding, Saccharomyces cerevisiae Proteins, Saccharomyces cerevisiae, Telomere, Oligonucleotides, Telomerase, Telomere-Binding Proteins},
  author = {Yun Wu and Virginia Zakian},
  title = {The telomeric Cdc13 protein interacts directly with the telomerase subunit Est1 to bring it to telomeric DNA ends in vitro.},
  abstract = { In Saccharomyces cerevisiae, a Cdc13-Est1 interaction is proposed to mediate recruitment of telomerase to DNA ends. Here we provide unique in vitro evidence for this model by demonstrating a direct interaction between purified Cdc13 and Est1. The Cdc13-Est1 interaction is specific and requires the in vivo defined Cdc13 recruitment domain. Moreover, in the absence of this interaction, Est1 is excluded from telomeric single-stranded (ss)DNA. The apparent association constand (K(d)) between Est1 and a Cdc13-telomeric ssDNA complex was \~{}250 nM. In G2 phase cells, where telomerase is active, Cdc13 and Est1 were sufficiently abundant (\~{}420 and \~{}110 copies per cell, respectively) to support complex formation. Interaction between Cdc13 and Est1 was unchanged by three telomerase-deficient mutations, Cdc13(E252K) (cdc13-2), Est1(K444E) (est1-60), and Cdc13(S249,255D), indicating that their telomerase null phenotypes are not due to loss of the Cdc13-Est1 interaction. These data recapitulate in vitro the first step in telomerase recruitment to telomeric ssDNA and suggest that this step is necessary to recruit telomerase to DNA ends. },
  year = {2011},
  journal = {Proc Natl Acad Sci U S A},
  volume = {108},
  pages = {20362-9},
  month = {12/2011},
  issn = {1091-6490},
  doi = {10.1073/pnas.1100281108},
  language = {eng},
}