Linked Life Data

16677300

Source:http://linkedlifedata.com/resource/pubmed/id/16677300

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2006-5-8
pubmed:abstractText
A type I restriction-modification enzyme will bind to an unmethylated target sequence in DNA and, while still bound to the target, translocate DNA through the protein complex in both directions. DNA breakage occurs when two translocating complexes collide. However, if type I restriction-modification systems bind to unmodified target sequences within the resident bacterial chromosome, as opposed to incoming 'foreign' DNA, their activity is curtailed; a process known as restriction alleviation (RA). We have identified two genes in Escherichia coli, rnhA and recG, mutations in which lead to the alleviation of restriction. Induction of RA in response to these mutations is consistent with the production of unmodified target sequences following DNA synthesis associated with both homologous recombination and R-loop formation. This implies that a normal function of RA is to protect the bacterial chromosome when recombination generates unmodified products. For EcoKI, our experiments demonstrate the contribution of two pathways that serve to protect unmodified DNA in the bacterial chromosome: the primary pathway in which ClpXP degrades the restriction endonuclease and a mechanism dependent on the lar gene within Rac, a resident, defective prophage of E. coli K-12. Previously, the potential of the second pathway has only been demonstrated when expression of lar has been elevated. Our data identify the effect of lar from the repressed prophage.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
60
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
883-93
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
Control of the endonuclease activity of type I restriction-modification systems is required to maintain chromosome integrity following homologous recombination.
pubmed:affiliation
Institute of Structural and Molecular Biology, University of Edinburgh, Edinburgh, Scotland, UK. Garry.Blakely@ed.ac.uk
pubmed:publicationType
Journal Article