Linked Life Data

2698831

Source:http://linkedlifedata.com/resource/pubmed/id/2698831

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1990-5-17
pubmed:abstractText
Telomeres stabilize chromosomal ends and allow their complete replication in vivo. In diverse eukaryotes, the essential telomeric DNA sequence consists of variable numbers of tandem repeats of simple, G + C rich sequences, with a strong strand bias of G residues on the strand oriented 5' to 3' toward the chromosomal terminus. This strand forms a protruding 3' over-hang at the chromosomal terminus in three different eukaryotes analyzed. Analysis of yeast and protozoan telomeres showed that telomeres are dynamic structures in vivo, being acted on by shortening and lengthening activities. We previously identified and partially purified an enzymatic activity, telomere terminal transferase, or telomerase, from the ciliate Tetrahymena. Telomerase is a ribonucleoprotein enzyme with essential RNA and protein components. This activity adds repeats of the Tetrahymena telomeric sequence, TTGGGG, onto the 3' end of a single-stranded DNA primer consisting of a few repeats of the G-rich strand of known telomeric, and telomere-like, sequences. The shortest oligonucleotide active as a primer was the decamer G4T2G4. Structural analysis of synthetic DNA oligonucleotides that are active as primers showed that they all formed discrete intramolecular foldback structures at temperatures below 40 degrees C. Addition of TTGGGG repeats occurs one nucleotide at a time by de novo synthesis, which is not templated by the DNA primer. Up to 8000 nucleotides of G4T2 repeats were added to the primer in vitro. We discuss the implications of this finding for regulation of telomerase in vivo and a model for telomere elongation by telomerase.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0831-2796
pubmed:author
pubmed:issnType
Print
pubmed:volume
31
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
553-60
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Recognition and elongation of telomeres by telomerase.
pubmed:affiliation
Department of Molecular Biology, University of California, Berkeley 94720.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.