The reverse transcriptase component of the Tetrahymena telomerase ribonucleoprotein complex.
Telomerase is a eukaryotic reverse transcriptase that adds simple sequence repeats to chromosome ends by copying a template sequence within the RNA component of the enzyme. We describe here the identification of a Tetrahymena telomerase protein with reverse transcriptase motifs, p133. This subunit is associated with the previously identified Tetrahymena telomerase RNA and the telomerase proteins p80 and p95 in immunoprecipitation assays. Therefore, all four known Tetrahymena telomerase components are present in a single complex. Expressed in rabbit reticulocyte lysate, recombinant p133 and telomerase RNA alone catalyze a reverse transcriptase activity with some similarities to and some differences from native Tetrahymena telomerase. These experiments suggest a complexity of telomerase structure and function.
Department of Molecular and Cell Biology, 401 Barker Hall, University of California, Berkeley, CA 94720-3204, USA. kcollins@socrates.berkeley.edu
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000378:metabolism; D003001:Cloning, Molecular; D017931:DNA Primers; D008969:Molecular Sequence Data; D011485:Protein Binding; D016053:RNA, Protozoan / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D019098:Telomerase / Q000235:genetics / Q000378:metabolism*; D016808:Tetrahymena thermophila / Q000201:enzymology*
D002352:Carrier Proteins; D017931:DNA Primers; D016053:RNA, Protozoan; D011994:Recombinant Proteins; D019098:Telomerase; C498417:telomerase p80 protein, Tetrahymena