Linked Life Data

6753948

Source:http://linkedlifedata.com/resource/pubmed/id/6753948

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8-9
pubmed:dateCreated
1983-1-27
pubmed:abstractText
Pyrimidine dimer (PD)-DNA glycosylase activity has been reported in both the M. luteus and phage T4 UV endonucleases. In the present studies the T4 PD-DNA glycosylase has been purified close to physical homogeneity using an assay that measures the release of free thymine from UV-irradiated poly ([H5] dT):poly (dA), after the photo-reversal of thymine-thymine dimers. The activity has also been demonstrated in vivo following infection of UV-irradiated E. coli uvr- cells with phage T4. Under these conditions the T4 PD-DNA glycosylase accounts quantitatively for all thymine-containing PD excised from [3H] labeled E. coli DNA. In vitro the T4 PD-DNA glycosylase has an associated AP endonuclease activity that incises UV-irradiated DNA 3 to the apyrimidinic sites created by the glycosylase. However, the glycosylase/AP endonuclease reaction mechanism in vitro does not appear to be a concerted one. In addition, a T4 phage with a temperature-sensitive mutation in the denV gene shows wild-type levels of survival at the permissive temperature, despite the fact that in vitro, extracts of E. coli infected with this mutant show no detectable phage-coded AP endonuclease at 28 degrees C. Thus the exact role of the T4 AP endonuclease in the incision of UV-irradiated DNA dimer in vivo is not clear. The ratio of excised non-containing nucleotides to dimer-containing nucleotides following infection of UV-irradiated E. coli with phage T4 denV+ yields a calculated average repair patch size of approximately 7 nucleotides. In contrast, the calculated average patch size in uninfected E. coli is approximately 70 nucleotides. Thus the extent of excision/resynthesis of UV-irradiated DNA may be determined by the specific mode of incision of the DNA at PD. When uninfected E. coli (uvr+) is exposed to UV radiation, a fraction of the excised thymine-containing PD contain photolabile thymine, suggesting the presence of PD-DNA glycosylase in E. coli. The role of this putative activity in the metabolism of UV-irradiated DNA is under investigation.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/DNA Glycosylases, http://linkedlifedata.com/resource/pubmed/chemical/DNA Polymerase I, http://linkedlifedata.com/resource/pubmed/chemical/DNA-(Apurinic or Apyrimidinic..., http://linkedlifedata.com/resource/pubmed/chemical/Deoxyribonuclease IV (Phage..., http://linkedlifedata.com/resource/pubmed/chemical/Endodeoxyribonucleases, http://linkedlifedata.com/resource/pubmed/chemical/Escherichia coli Proteins, http://linkedlifedata.com/resource/pubmed/chemical/N-Glycosyl Hydrolases, http://linkedlifedata.com/resource/pubmed/chemical/Poly dA-dT, http://linkedlifedata.com/resource/pubmed/chemical/Tritium, http://linkedlifedata.com/resource/pubmed/chemical/deoxyribopyrimidine endonucleosidase, http://linkedlifedata.com/resource/pubmed/chemical/endonuclease IV, E coli
pubmed:status
MEDLINE
pubmed:issn
0300-9084
pubmed:author
pubmed:issnType
Print
pubmed:volume
64
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
643-54
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:articleTitle
Pyrimidine dimer-DNA glycosylases: studies on bacteriophage T4-infected and on uninfected Escherichia coli.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't