Linked Life Data

18707026

Source:http://linkedlifedata.com/resource/pubmed/id/18707026

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2008-9-22
pubmed:abstractText
Transcription-coupled DNA repair is a mechanism by which bulky DNA lesions that block transcription by RNA polymerase are prioritised for removal by the nucleotide excision repair apparatus. The trigger is thought to be the presence of an irreversibly blocked transcription complex, which is recognised by a transcription-repair coupling factor. Many common DNA lesions do not block transcription, but are bypassed with varying degrees of efficiency and with potentially mutagenic effects on the RNA transcripts that are produced. The effect of the bacterial transcription-repair coupling factor, Mfd, at such lesions is not known: it has been suggested that Mfd may promote mutagenesis by increasing the efficiency with which RNA polymerase bypasses non-bulky lesions, but it has also been reported that 8-oxoguanine, a major product of oxidative DNA damage that is efficiently bypassed by RNA polymerase, is subject to Mfd-dependent transcription-coupled repair in Escherichia coli. We have investigated the effect of Mfd during transcription of templates containing 8-oxoguanine, and various other non-bulky lesions. We show that an 8-oxoguanine in the template strand induces a transient pause in transcription, and that Mfd neither increases nor decreases the efficiency with which RNA polymerase bypasses the lesion. We also show that Mfd can displace a transcription complex stalled at a single strand nick, and that it decreases the efficiency with which RNA polymerase bypasses an abasic site. These activities are not affected by transcription rate, as similar results were obtained using "fast" and "slow" mutant RNA polymerases. Our findings suggest that 8-oxoguanine is unlikely to be directly targeted by the transcription-coupled repair pathway, and identify a potential role for Mfd in reducing the level of transcriptional mutagenesis caused by abasic sites.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1568-7864
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
7
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1670-9
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Effects of the bacterial transcription-repair coupling factor during transcription of DNA containing non-bulky lesions.
pubmed:affiliation
DNA-protein Interactions Unit, Department of Biochemistry, University of Bristol, Bristol, UK.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't