title: Purification of Tetrahymena telomerase and cloning of genes encoding the two protein components of the enzyme.
abstract: Telomerase is a ribonucleoprotein DNA polymerase that catalyzes the de novo synthesis of telomeric simple sequence repeats. We describe the purification of telomerase and the cloning of cDNAs encoding two protein subunits from the ciliate Tetrahymena. Two proteins of 80 and 95 kDa copurified and coimmunoprecipitated with telomerase activity and the previously identified Tetrahymena telomerase RNA. The p95 subunit specifically cross-linked to a radiolabeled telomeric DNA primer, while the p80 subunit specifically bound to radiolabeled telomerase RNA. At the primary sequence level, the two telomerase proteins share only limited homologies with other polymerases and polymerase accessory factors.
authors.affiliation: Cold Spring Harbor Laboratory, New York 11724, USA.
authors.forename: K
authors.initials: K
authors.lastname: Collins
authors.forename: R
authors.initials: R
authors.lastname: Kobayashi
authors.forename: C W
authors.initials: CW
authors.lastname: Greider
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000913:Antibodies, Protozoan; D001483:Base Sequence; D003001:Cloning, Molecular; D004253:DNA Nucleotidylexotransferase / Q000235:genetics* / Q000276:immunology; D018076:DNA, Complementary / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D017125:Genes, Protozoan / Q000235:genetics*; D015151:Immunoblotting; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011233:Precipitin Tests; D011487:Protein Conformation; D015800:Protozoan Proteins / Q000235:genetics*; D016053:RNA, Protozoan / Q000378:metabolism; D012261:Ribonucleoproteins / Q000235:genetics* / Q000302:isolation & purification; D017421:Sequence Analysis; D016808:Tetrahymena thermophila / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D000913:Antibodies, Protozoan; D018076:DNA, Complementary; D015800:Protozoan Proteins; D016053:RNA, Protozoan; D012261:Ribonucleoproteins; D004253:DNA Nucleotidylexotransferase