Est1 is a protein which recruits or activates telomerase at the site of polymerisation [1]. Structurally it resembles a TPR-like repeat.
Est1 is directly involved in telomere replication. It associates with telomerase and, during its interaction with CDC13, telomerase activity is promoted [PUBMED:12169735, PUBMED:12454059].
Taggart AK, Teng SC, Zakian VA; , Science. 2002;297:1023-1026.: Est1p as a cell cycle-regulated activator of telomere-bound telomerase. PUBMED:12169735 EPMC:12169735 .
Evans SK, Lundblad V; , Genetics. 2002;162:1101-1115.: The Est1 subunit of Saccharomyces cerevisiae telomerase makes multiple contributions to telomere length maintenance. PUBMED:12454059 EPMC:12454059 .
Beernink HT, Miller K, Deshpande A, Bucher P, Cooper JP; , Curr Biol. 2003;13:575-580.: Telomere maintenance in fission yeast requires an Est1 ortholog. PUBMED:12676088 EPMC:12676088.