Isolation of a bacterial enzyme which releases adenine containing photoproducts from UV-irradiated DNA
- West Virginia Univ., Morgantown (United States)
It is generally assumed that DNA purines are relativity inert to photochemical alterations. However, several purine photoproducts have been characterized, including two distinct adenine dimers. Using UV-irradiated poly(dA)-poly(dT) labeled with (8-{sup 3}H dATP), as a substrate, an enzymatic activity for adenine-containing photoproducts was isolated from E. coli. The enzymatic activity specific for UV-irradiated poly(dA)-poly(dT) was separated from other UV-DNA incising activities by ion-exchange chromatography. The partially purified enzyme releases TCA-soluble material from UV-irradiated poly(dA)-poly(dT). The enzyme does not release radioactive material from poly(dA)-poly(dT) radiolabeled with (methyl-{sup 3}H)dTTP. DNA sequence analysis, has shown that the partially purified enzyme incises UV-irradiated DNA adjacent to adenines in regions of the substrate containing multiple adenines. These data indicate that the enzymatic activity is directed against adenine photoproducts. Since the radiolabel is retained upon UV-irradiation of the polynucleotide, this suggests that the structure of the recognized photoproduct is not 8,8-adenine dehydrodimer. The nature of the enzyme-released photoproduct is currently under investigation.
- OSTI ID:
- 5375445
- Report Number(s):
- CONF-9104107--
- Journal Information:
- FASEB Journal (Federation of American Societies for Experimental Biology); (United States), Journal Name: FASEB Journal (Federation of American Societies for Experimental Biology); (United States) Vol. 5:4; ISSN FAJOE; ISSN 0892-6638
- Country of Publication:
- United States
- Language:
- English
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Cells
& Tissue Culture
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ADENINES
AMINES
ANTIMETABOLITES
AROMATICS
ATP
AZAARENES
BACTERIA
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
CHROMATOGRAPHY
DNA
DNA SEQUENCING
DRUGS
ELECTROMAGNETIC RADIATION
ENZYME ACTIVITY
ENZYMES
ESCHERICHIA COLI
GENETIC EFFECTS
GENETIC RADIATION EFFECTS
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
ION EXCHANGE CHROMATOGRAPHY
ISOTOPE APPLICATIONS
MICROORGANISMS
NUCLEIC ACIDS
NUCLEOTIDES
NUCLEOTIDYLTRANSFERASES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOSPHORUS-GROUP TRANSFERASES
POLYMERASES
PROTEINS
PURINES
RADIATION EFFECTS
RADIATIONS
SEPARATION PROCESSES
STRUCTURAL CHEMICAL ANALYSIS
TRACER TECHNIQUES
TRANSFERASES
TRITIUM COMPOUNDS
ULTRAVIOLET RADIATION