The Role of Inducible DNA Repair in W-Reactivation and Related Phenomena

Photoreactivation of ultraviolet-irradiated, plasmid-bearing, and plasmid-free strains of Bacillus anthracis

“…Other plasmids render their host more sensitive to UV, and other plasmids have no effect on UV sensitivity. Some plasmids are known to carry genes which code for repair enzymes (13). When strains of E. coli, lysogenic for a transducing phage carrying the phr gene, are induced, they can produce approximately 2,000 times the normal levels of photoreactivating enzyme (27).…”

“…Irradiation of cells with UV light (220 to 300 nm) can result in the formation of pyrimidine dimers in the DNA, leading to mutagenic changes or cell death. Several repair pathways exist for the repair of UV-induced DNA damage, including photoreactivation, excision repair, recombinational repair, and inducible error-prone repair (13). Photoreactivation is the error-free, light-dependent (300 to 500 nm), enzymatic monomerization of UV-induced pyrimidine dimers.…”

Photoreactivating capacity in Clostridium butyricum and Clostridium acetobutylicum

“…light (230-300 nm) can result in formation of pyrimidine dimers in the DNA, leading to mutagenic changes or cell death. Several repair pathways exist for the repair of u.v.-induced damage, including photoreactivation, excision repair, recombinational repair and inducible errorprone repair (Witkin 1976;Knudson 1983;Walker 1984).…”

Photoreactivation of UV-irradiated Legionella pneumophila and other Legionella species

“…Irradiation of cells with UV light (220 to 320 nm) can result in the formation of intrastrand cyclobutyl-pyrimidine dimers in the DNA, leading to mutagenic changes or cell death. Several repair pathways exist for the repair of UV-induced DNA damage including photoreactivation, excision repair, recombinational repair, and inducible error-prone repair (28). Photoreactivation is the error-free, light-dependent (300 to 600 nm), enzymatic monomerization of UV-induced pyrimidine dimers.…”