Open AccessRole of exonuclease III and endonuclease IV in repair of pyrimidine dimers initiated by bacteriophage T4 pyrimidine dimer-DNA glycosylase
Author(s) -
S M Saporito,
M Gedenk,
Richard P. Cunningham
Publication year - 1989
Publication title -
journal of bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.652
H-Index - 246
eISSN - 1067-8832
pISSN - 0021-9193
DOI - 10.1128/jb.171.5.2542-2546.1989
Subject(s) - dna glycosylase , pyrimidine dimer , biology , exonuclease , mutant , microbiology and biotechnology , nuclease , endonuclease , ap site , escherichia coli , dna , recbcd , wild type , dna repair , biochemistry , gene , dna polymerase
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.