Linked Life Data

9740781

Source:http://linkedlifedata.com/resource/pubmed/id/9740781

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1998-10-13
pubmed:abstractText
Bacteriophage lambda-derived replicons can replicate in Escherichia coli cells as plasmids. In the control of replication of these plasmids, an important role was ascribed to the lambda Cro repressor autoregulatory loop. However, the oR/pR-cro-tR-cII' region could be replaced by the ptetA promoter under the control of the TetR repressor, producing plasmid pTClambda. Here, we demonstrate that stable maintenance of pTClambda depends on the host DnaA function because deletion of one of DnaA-binding sequences present in pTClambda resulted in a decrease in the plasmid (pTClambda) copy number and poor maintenance of pTClambda in E. coli. Moreover, in contrast to the replication of the wild-type lambda plasmid, previously found to be positively regulated by DnaA (acting on a relaxed DnaA box situated immediately downstream of the pR promoter), the replication of pTC plasmids (devoid of pR) was found to be negatively regulated by DnaA. Contrary to wild-type lambda plasmids, in cells harboring lambda cro[temperature-sensitive (ts)] or pTClambda (but not pTClambda) plasmid, the lambda replication complex was heat shock resistant; this complex, however, disassembled after inactivation of DnaA function. This disassembly was blocked by DNA gyrase inhibitors. According to our model outlined previously, we propose that the heat shock resistance of the replication complex of lambdacro- plasmids depends on the interaction of the DNA-bound DnaA protein with the DNA-bound lambda replication complex. The replication complex-DnaA-lambda DNA structure may be directly related to the role of DnaA as the Cro-replacing negative regulator of lambdacro- plasmid replication.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0042-6822
pubmed:author
pubmed:copyrightInfo
Copyright 1998 Academic Press.
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
249
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
98-107
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
DnaA-mediated regulation of phage lambda-derived replicons in the absence of pR and Cro function.
pubmed:affiliation
Department of Molecular Biology, University of Gdañsk, Kladki 24, Gdañsk, 80-822, Poland.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't