Linked Life Data

9737919

Source:http://linkedlifedata.com/resource/pubmed/id/9737919

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1998-10-21
pubmed:abstractText
The retrohoming of the yeast mtDNA intron aI1 occurs by a target DNA-primed reverse transcription (TPRT) mechanism in which the intron RNA reverse splices directly into the recipient DNA and is then copied by the intron-encoded reverse transcriptase. Here, we carried out biochemical characterization of the intron-encoded reverse transcriptase and site-specific DNA endonuclease activities required for this process. We show that the aI1 reverse transcriptase has high TPRT activity in the presence of appropriate DNA target sites, but differs from the closely related reverse transcriptase encoded by the yeast aI2 intron in being unable to use artificial substrates efficiently. Characterization of TPRT products shows that the fully reverse spliced intron RNA is an efficient template for cDNA synthesis, while reverse transcription of partially reverse spliced intron RNA is impeded by the branch point. Novel features of the aI1 reaction include a prominent open-circular product in which cDNAs are incorporated at a nick at the antisense-strand cleavage site. The aI1 endonuclease activity, which catalyzes the DNA cleavage and reverse splicing reactions, is associated with ribonucleoprotein particles containing the intron-encoded protein and the excised intron RNA. As shown for the aI2 endonuclease, both the RNA and protein components are used for DNA target site recognition, but the aI1 protein has less stringent nucleotide sequence requirements for the reverse splicing reaction. Finally, perhaps reflecting this relaxed target specificity, in vitro experiments show that aI1 can reverse splice directly into ectopic mtDNA transposition sites, consistent with the previously suggested possibility that this mechanism is used for ectopic transposition of group II introns in vivo.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0022-2836
pubmed:author
pubmed:copyrightInfo
Copyright 1998 Academic Press.
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
282
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
505-23
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Group II intron mobility in yeast mitochondria: target DNA-primed reverse transcription activity of aI1 and reverse splicing into DNA transposition sites in vitro.
pubmed:affiliation
Departments of Molecular Genetics, Biochemistry and Medical Biochemistry, The Ohio State University, 484 West Twelfth Avenue, Columbus, Ohio, 43210, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't