Linked Life Data

9694887

Source:http://linkedlifedata.com/resource/pubmed/id/9694887

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
33
pubmed:dateCreated
1998-9-14
pubmed:abstractText
DNA base damage products either formed spontaneously or as a result of exposure to various genotoxic agents were examined for their effects on Escherichia coli RNA polymerase-mediated transcription in vitro. Uracil, O6-methylguanine (O6-meG), and 8-oxoguanine (8-oxoG) were placed at specific sites downstream from the transcriptional start site on the transcribed strand of a duplex template under the control of the strong tac promoter. In vitro, single-round transcription experiments carried out with purified E. coli RNA polymerase revealed efficient bypass at the three lesions examined and subsequent generation of full-length runoff transcripts. Transcript sequence analysis revealed that E. coli RNA polymerase inserted primarily adenine into the transcript opposite to uracil, uracil opposite to O6-meG, and either adenine or cytosine opposite to 8-oxoG. Thus, a uracil in the DNA template resulted in a G-to-A transition mutation in the lesion bypass product whereas O6-meG produced a C-to-U transition mutation and 8-oxoG generated either the correct transcriptional product or a C-to-A transversion mutation. When 8-oxoG was placed within close proximity to the transcriptional start site (within the region required for effective promoter clearance), a reduced of full-length, runoff transcript was observed, indicative of lower promoter clearance. Taken together, these results demonstrate that the DNA base damages studied here may exert significant in vivo effects on gene expression and DNA repair with respect to the production of mutant proteins (transcriptional mutagenesis), or decreased levels of expressed proteins.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
14
pubmed:volume
273
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
21276-81
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Effects of nonbulky DNA base damages on Escherichia coli RNA polymerase-mediated elongation and promoter clearance.
pubmed:affiliation
Graduate Program in Genetics and Molecular Biology, Emory University School of Medicine, Atlanta, Georgia 30322, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.