Linked Life Data

8798393

Source:http://linkedlifedata.com/resource/pubmed/id/8798393

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
37
pubmed:dateCreated
1996-11-7
pubmed:abstractText
Genome heterogeneity in retroviruses derives from poor fidelity of the reverse transcriptase (RT) and recombination via RT-catalyzed strand transfer synthesis. RTs lack proofreading ability, and they proficiently extend primers with mismatched termini. Recombination reactions carried out in vitro are accompanied by a high frequency of base substitution errors, suggesting a relationship. Here we provide evidence that misincorporation during RNA-directed DNA synthesis promotes strand transfer recombination. Experiments involved measurement of DNA synthesis, RNase H-directed cleavage, and strand transfer synthesis from preformed mismatched primers on RNA templates by human immunodeficiency virus (HIV) RT in vitro. A significant pause in synthesis occurred from a G(primer). rA(template) mismatch compared to the synthesis from a correctly paired (T.A) primer. The misincorporation-induced pause allowed an unusually large area of RT-RNase H-directed cleavage of the template RNA beneath the primer. Strand transfer to an acceptor molecule with sequence identical to the template RNA was about 50% more efficient than if the primer had had a correctly paired terminus. Overall transfer was measured over a large region of homology. Assuming that enhanced transfer occurs primarily at the site of the mismatch, the actual increase in transfer at that site must have been 1-2 orders of magnitude. Inclusion of a different acceptor molecule with complete complementarity to the originally mismatched 3' primer terminus resulted in an additional 2-fold increase in strand transfer efficiency. Overall, these results suggest the mechanism by which misincorporation during minus strand DNA synthesis in retroviral replication would promote high frequency recombination.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
13
pubmed:volume
271
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
22331-8
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Misincorporation by HIV-1 reverse transcriptase promotes recombination via strand transfer synthesis.
pubmed:affiliation
Department of Biochemistry, University of Rochester, Rochester, New York 14642, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.