The effect of purified Escherichia coli DNA photolyase on the UV light-induced pyrimidine-pyrimidone (6-4) photoproduct and cyclobutane pyrimidine dimer was investigated in vitro using enzyme purified from cells carrying the cloned phr gene (map position, 15.7 min). Photoproducts were examined both as site-specific lesions in end-labeled DNA and as chromatographically identified products in uni...

Kelner (Sci. American, 184, 22, 1951) reported that the reactivation spectrum for Streptomycee gri8eu is very similar to the absorption spectrum for iron porphyrin systems, while that of Escherichia coli is somewhat different. Latarjet et al. (J. Gen. Physiol., 35, 455, 1952) reactivated irradiated microorganisms by catalase, and Berger et al. (J. Bacteriol., 65, 539, 1953) found that sodium az...

Considerable evidence exists which is consistent with the picture that the chloroplast system of E1uglcna is unider autonomous genietic control. This includes studies of ultraviolet inactivationi anid photoreactivation of chloroplast inheritanice (7, 10. 13, 14) and the demonlstration of a unique species of chloroplast-associated DNA (3, 4, s5, 9, 11). Evidence has been presented for distinct c...

The combined disinfection process of ultraviolet and sodium hypochlorite has more advantages than the single method in reducing disinfectant dosage, shortening reaction time, resisting impact water quality changes inhibiting light reactivation microorganisms. Given this, using secondary effluent a sewage plant as research object, efficiency was investigated. experimental results showed that ina...

Six uvr mutants of Saccharomyces cerevisiae with hypersensitivity to ultraviolet (UV) light were isolated after mutagen treatment with ethylmethanesulfonate. UV sensitivity ranges from moderate to extreme, and four of the mutants are also sensitive to nitrous acid. Ranking in terms of UV sensitivity does not parallel ranking in terms of nitrous acid sensitivity. Homozygous diploid mutant strain...