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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2000-9-12
pubmed:abstractText
The Escherichia coli UVM (UV Modulation of mutagenesis) response is a DNA damage-inducible mutagenic pathway detected as significantly increased mutagenesis at 3,N4-ethenocytosine (epsilon C) lesions borne on transfected single-stranded M13 vector DNA. All major classes of DNA-damaging agents can induce UVM, and the phenomenon is independent of previously characterized mutagenic responses in E. coli. To understand this phenomenon further, we set out to identify and characterize mutants in the UVM response. Screening a mutant bank of cells defective for 1-methyl-3-nitro-1-nitrosoguanidine-inducible genes revealed that defects in the recN gene cause a constitutive elevation of mutagenesis at epsilon C residues. In contrast to normal cells that show approximately 6% mutagenesis at epsilon C lesions, but approximately 60% upon UVM induction, recN-defective strains display approximately 50% mutagenesis at epsilon C lesion sites in untreated cells. However, the recN-mediated mutagenesis response was found to require the recA gene and the umuDC genes, and could be suppressed in the presence of a plasmid harbouring the SOS transcriptional repressor LexA. These results imply that recN cells are constitutively active for SOS mutagenesis functions. The observation that epsilonC mutagenesis is enhanced in recN cells confirms previous findings that mutagenesis at epsilonC can also be independently elevated by the SOS pathway.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
37
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
680-6
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Escherichia coli cells defective for the recN gene display constitutive elevation of mutagenesis at 3,N(4)-ethenocytosine via an SOS-induced mechanism.
pubmed:affiliation
Department of Microbiology and Molecular Genetics, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, 185 South Orange Avenue MSB-F607, Newark, NJ 07103-2714, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.