Linked Life Data

1995629

Source:http://linkedlifedata.com/resource/pubmed/id/1995629

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1991-3-27
pubmed:abstractText
A general repair process for DNA heteroduplexes has been detected in HeLa cell extracts. Using a variety of M13mp2 DNA substrates containing single-base mismatches and extra nucleotides, extensive repair is observed after incubation with HeLa cell cytoplasmic extracts and subsequent transfection of bacterial cells with the treated DNA. Most, but not all, mispairs as well as two frameshift heteroduplexes are repaired efficiently. Parallel measurements of repair in HeLa extracts and in Escherichia coli suggest that repair specificities are similar for the two systems. The presence of a nick in the molecule is required for efficient repair in HeLa cell extracts, and the strand containing the nick is the predominantly repaired strand. Mismatch-dependent DNA synthesis is observed when radiolabeled restriction fragments, produced by reaction of the extract with heteroduplex and homoduplex molecules, are compared. Specific labeling of fragments, representing a region of approximately 1,000 base pairs and containing the nick and the mismatch, is detected for the heteroduplex substrate but not the homoduplex. The repair reaction is complete after 20 min and requires added Mg2+, ATP, and an ATP-regenerating system, but not dNTPs, which are present at sufficient levels in the extract. An inhibitor of DNA polymerase beta, dideoxythimidine 5'-triphosphate, does not inhibit mismatch-specific DNA synthesis. Aphidicolin, an inhibitor of DNA polymerases alpha, delta, and epsilom, inhibits both semiconservative replication and repair synthesis in the extract. Butylphenyl-dGTP also inhibits both replicative and repair synthesis but at a concentration known to inhibit DNA polymerase alpha preferentially rather than delta or epsilon. This suggests that DNA polymerase alpha may function in mismatch repair.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
266
pubmed:geneSymbol
lacZalpha
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3744-51
pubmed:dateRevised
2006-5-1
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Heteroduplex repair in extracts of human HeLa cells.
pubmed:affiliation
Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709.
pubmed:publicationType
Journal Article