Stimulation of yeast telomerase activity by the ever shorter telomere 3 (Est3) subunit is dependent on direct interaction with the catalytic protein Est2.

ABSTRACT: Telomerase is a multisubunit enzyme that maintains genome stability through its role in telomere replication. Although the Est3 protein is long recognized as an essential telomerase component, how it associates with and functions in the telomerase complex has remained enigmatic. Here we provide the first evidence of a direct interaction between Saccharomyces cerevisiae Est3p and the catalytic protein subunit (Est2p) by demonstrating that recombinant Est3p binds the purified telomerase essential N-terminal (TEN) domain of Est2p in vitro. Mutations in a small cluster of amino acids predicted to lie on the surface of Est3p disrupt this interaction with Est2p, reduce assembly of Est3p with telomerase in vivo, and cause telomere shortening and senescence. We also show that recombinant Est3p sti

SUBMITTER: Talley JM 

PROVIDER: S-EPMC3143607 | biostudies-literature | 2011 Jul

REPOSITORIES: biostudies-literature