title: Role of exonuclease III and endonuclease IV in repair of pyrimidine dimers initiated by bacteriophage T4 pyrimidine dimer-DNA glycosylase.
abstract: The role of exonuclease III and endonuclease IV in the repair of pyrimidine dimers in bacteriophage T4-infected Escherichia coli was examined. UV-irradiated T4 showed reduced survival when plated on an xth nfo double mutant but showed wild-type survival on either single mutant. T4 denV phage were equally sensitive when plated on wild-type E. coli or an xth nfo double mutant, suggesting that these endonucleases function in the same repair pathway as T4 pyrimidine dimer-DNA glycosylase. A uvrA mutant of E. coli in which the repair of pyrimidine dimers was dependent on the T4 denV gene carried on a plasmid was constructed. Neither an xth nor an nfo derivative of this strain was more sensitive than the parental strain to UV irradiation. We were unable to construct a uvrA xth nfo triple mutant. In addition, T4, which turns off the host UvrABC excision nuclease, showed reduced plating efficiency on an xth nfo double mutant.
authors: Department of Biological Sciences, State University of New York, Albany 12222.
authors: S M
authors: SM
authors: Saporito
authors: M
authors: M
authors: Gedenk
authors: R P
authors: RP
authors: Cunningham
mesh_terms: D001080:Apurinic Acid / Q000378:metabolism*; D045647:DNA Glycosylases; D004260:DNA Repair; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; D043223:Deoxyribonuclease IV (Phage T4-Induced); D004706:Endodeoxyribonucleases / Q000502:physiology*; D004926:Escherichia coli / Q000235:genetics; D029968:Escherichia coli Proteins; D005090:Exodeoxyribonucleases / Q000502:physiology*; D009154:Mutation; D009699:N-Glycosyl Hydrolases / Q000378:metabolism*; D011119:Polynucleotides / Q000378:metabolism*; D011740:Pyrimidine Dimers / Q000378:metabolism*; D013604:T-Phages / Q000201:enzymology* / Q000235:genetics / Q000528:radiation effects; D014466:Ultraviolet Rays; D014779:Virus Replication
chemical_list: D029968:Escherichia coli Proteins; D011119:Polynucleotides; D011740:Pyrimidine Dimers; D001080:Apurinic Acid; D004706:Endodeoxyribonucleases; D005090:Exodeoxyribonucleases; C020133:exodeoxyribonuclease III; D043223:Deoxyribonuclease IV (Phage T4-Induced); C468972:endonuclease IV, E coli; D045647:DNA Glycosylases; D009699:N-Glycosyl Hydrolases; C036401:deoxyribopyrimidine endonucleosidase; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase