Open AccessThe catalytic subunit of yeast telomerase
Author(s) -
Christopher M. Counter,
Matthew Meyerson,
Elinor Ng Eaton,
Robert A. Weinberg
Publication year - 1997
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.94.17.9202
Subject(s) - telomerase , protein subunit , telomerase rna component , telomere , polymerase , saccharomyces cerevisiae , biology , dna polymerase , rna , biochemistry , microbiology and biotechnology , yeast , specificity factor , telomerase reverse transcriptase , dna , gene , rna polymerase , genetics
Telomerase is an RNA-directed DNA polymerase, composed of RNA and protein subunits, that replicates the telomere ends of linear eukaryotic chromosomes. Using a genetic strategy described here, we identify the product of theEST2 gene, Est2p, as a subunit of telomerase in the yeastSaccharomyces cerevisiae . Est2p is required for enzyme catalysis, as mutations inEST2 were found to result in the absence of telomerase activity. Immunochemical experiments show that Est2p is an integral subunit of the telomerase enzyme. Critical catalytic residues present in RNA-directed DNA polymerases are conserved in Est2p; mutation of one such residue abolishes telomerase activity, suggesting a direct catalytic role for Est2p.