Incision by UvrAB excinuclease is a step in the path to mutagenesis by psoralen crosslinks in Escherichia coli
- Yale Univ., New Haven, CT (USA)
4,5{prime},8-Trimethylpsoralen (psoralen) plus near UV light produces interstrand crosslinks and monoadducts in DNA, both of which are mutagenic. In Escherichia coli, crosslinks are incised by UvrABC excinuclease, an event that can lead to homologous recombination and repair. To determine whether UvrABC incision of crosslinks is a step in the path to mutagenesis as well as repair, the effect of DNA homologous to a target gene on a plasmid was determined. The results show that psoralen-induced mutations were reduced to background levels by the presence of the gpt{sup +} homolog in the host chromosome. {Delta}gpt hosts that were constitutively induced for the SOS response yielded point mutations, whereas noninduced hosts yielded almost exclusively large deletions. Since crosslinks were estimated to be responsible for most of the mutations observed, the authors conclude that the premutagenic lesion of psoralen crosslinks is recombinagenic and therefore very likely to be the product of UvrABC incision.
- OSTI ID:
- 5440992
- Journal Information:
- Proceedings of the National Academy of Sciences of the United States of America; (USA), Journal Name: Proceedings of the National Academy of Sciences of the United States of America; (USA) Vol. 86:11; ISSN 0027-8424; ISSN PNASA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
Cells
& Tissue Culture
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ADDUCTS
ANTICOAGULANTS
BACTERIA
BIOCHEMISTRY
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CELL CONSTITUENTS
CHEMICAL REACTIONS
CHEMISTRY
COUMARINS
CROSS-LINKING
DNA ADDUCTS
DNA REPAIR
DNA-ASE
DRUGS
ELECTROMAGNETIC RADIATION
ENDONUCLEASES
ENZYMES
ESCHERICHIA COLI
ESTERASES
GENE AMPLIFICATION
GENE RECOMBINATION
HEMATOLOGIC AGENTS
HETEROCYCLIC COMPOUNDS
HYDROLASES
MICROORGANISMS
MUTAGENESIS
MUTATION FREQUENCY
NEAR ULTRAVIOLET RADIATION
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PHOSPHODIESTERASES
PLASMIDS
POLYMERIZATION
PSORALEN
RADIATION EFFECTS
RADIATIONS
RECOVERY
REPAIR
ULTRAVIOLET RADIATION