000114170 001__ 114170
000114170 005__ 20181203021019.0
000114170 0247_ $$2doi$$a10.1126/science.276.5312.561
000114170 037__ $$aARTICLE
000114170 245__ $$aReverse transcriptase motifs in the catalytic subunit of telomerase
000114170 269__ $$a1997
000114170 260__ $$c1997
000114170 336__ $$aJournal Articles
000114170 500__ $$aHoward Hughes Medical Institute, Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO 80309-0215, USA.
000114170 520__ $$aTelomerase is a ribonucleoprotein enzyme essential for the replication of chromosome termini in most eukaryotes. Telomerase RNA components have been identified from many organisms, but no protein component has been demonstrated to catalyze telomeric DNA extension. Telomerase was purified from Euplotes aediculatus, a ciliated protozoan, and one of its proteins was partially sequenced by nanoelectrospray tandem mass spectrometry. Cloning and sequence analysis of the corresponding gene revealed that this 123-kilodalton protein (p123) contains reverse transcriptase motifs. A yeast (Saccharomyces cerevisiae) homolog was found and subsequently identified as EST2 (ever shorter telomeres), deletion of which had independently been shown to produce telomere defects. Introduction of single amino acid substitutions within the reverse transcriptase motifs of Est2 protein led to telomere shortening and senescence in yeast, indicating that these motifs are important for catalysis of telomere elongation in vivo. In vitro telomeric DNA extension occurred with extracts from wild-type yeast but not from est2 mutants or mutants deficient in telomerase RNA. Thus, the reverse transcriptase protein fold, previously known to be involved in retroviral replication and retrotransposition, is essential for normal chromosome telomere replication in diverse eukaryotes.
000114170 700__ $$0240570$$g168670$$aLingner, J.
000114170 700__ $$aHughes, T. R.
000114170 700__ $$aShevchenko, A.
000114170 700__ $$aMann, M.
000114170 700__ $$aLundblad, V.
000114170 700__ $$aCech, T. R.
000114170 773__ $$j276$$tScience$$k5312$$q561-7
000114170 909C0 $$xU11159$$0252147$$pUPLIN
000114170 909CO $$pSV$$particle$$ooai:infoscience.tind.io:114170
000114170 937__ $$aUPLIN-ARTICLE-1997-002
000114170 970__ $$a46/UPLIN
000114170 973__ $$rREVIEWED$$sPUBLISHED$$aEPFL
000114170 980__ $$aARTICLE