Linked Life Data

9047364

Source:http://linkedlifedata.com/resource/pubmed/id/9047364

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1997-4-4
pubmed:abstractText
We have shown elsewhere that there is no, or very little, homology at the recombination sites in DNA gyrase-mediated illegitimate recombination in vitro. On the other hand, many reports have indicated that illegitimate recombination takes place between sequences with a short homology. To clarify this contradiction, we analyzed the mechanism of DNA gyrase-mediated illegitimate recombination in vivo, by isolating a temperature-sensitive gyrA mutant (gyrAhr1) that causes spontaneous illegitimate recombination at a higher frequency than that of the wild-type. This mutant also causes spontaneous induction of lambda prophage. It is therefore suggested that the gyrAhr1 mutation induces strand breaks in the chromosome, resulting in the formation of illegitimate recombinants. Analysis of the recombination junctions of lambdabio transducing phages formed spontaneously in the gyrAhr1 mutant revealed that the Escherichia coli bio and lambda recombination sites have an average homologous sequence of only 1.3 base pairs. This is the first indication that homology in vivo is not required for illegitimate recombination. On the other hand, a short homology of 8.4 bp, on average, was found in the junctions of lambdabio transducing phages formed spontaneously in the wild-type bacteria. When the gyrAhr1 mutant was irradiated with UV, short homologies were also detected in the junctions. We concluded that illegitimate recombination, which takes place spontaneously in the gyrAhr1 mutants, is distinguishable from spontaneous recombination in the wild-type and from UV-induced recombination in the mutant with regard to the requirement for short homology. We propose that short-homology-independent illegitimate recombination is mediated by subunit exchange between DNA gyrase, while short-homology-dependent recombination is triggered by double-strand breaks and completed by processing, annealing, and ligation of DNA ends.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
21
pubmed:volume
266
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
297-305
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Short-homology-independent illegitimate recombination in Escherichia coli: distinct mechanism from short-homology-dependent illegitimate recombination.
pubmed:affiliation
Department of Molecular Biology, Institute of Medical Science, University of Tokyo PO Takanawa, Japan.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't