Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1999-7-28
pubmed:abstractText
Electron microscopy (EM) was used to visualize intermediates of in vitro replication of closed circular DNA plasmids. Cell-free extracts were prepared from human cells that are proficient (IDH4, HeLa) or deficient (CTag) in bypass replication of pyrimidine dimers. The DNA substrate was either undamaged or contained a single cis, syn thymine dimer. This lesion was inserted 385 bp downstream from the center of the SV40 origin of replication and sited specifically in the template to the leading strand of the newly synthesized DNA. Products from 30 minute reactions were crosslinked with psoralen and UV, linearized with restriction enzymes and spread for EM visualization. Extended single-stranded DNA regions were detected in damaged molecules replicated by either bypass-proficient or deficient extracts. These regions could be coated with Escherichia coli single-stranded DNA binding protein. The length of duplex DNA from a unique restriction site to the single-stranded DNA region was that predicted from blockage of leading strand synthesis by the site-specific dimer. These results were confirmed by S1nuclease treatment of replication products linearized with single cutting restriction enzymes, followed by detection of the diagnostic fragments by gel electrophoresis. The absence of an extended single-stranded DNA region in replication forks that were clearly beyond the dimer was taken as evidence of bypass replication. These criteria were fulfilled in 17 % of the molecules replicated by the IDH4 extract.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0022-2836
pubmed:author
pubmed:copyrightInfo
Copyright 1999 Academic Press.
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
289
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1207-18
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Analysis of DNA replication forks encountering a pyrimidine dimer in the template to the leading strand.
pubmed:affiliation
Department of Pathology, University of North Carolina, Chapel Hill, USA. uncmcs@med.unc.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.