Isolation and characterization of an Escherichia coli ruv mutant which forms nonseptate filaments after low doses of ultraviolet light irradiation
Two ultraviolet light (uv)-sensitive mutants have been isolated from Escherichla coli K-12. These mutants, designated RuvA/sup -/ and RuvB/sup -/, were controlled by a gene located close to the his gene on the chromosome map. They were sensitive to uv (10to 20-fold increase) and slightly sensitive to gamma rays (3fold increase). Host cell reactivation, uv reactivation and genetic recombination were normal in these mutants. Irradiation of the mutants with uv resulted in the production of single-strand breaks in deoxyribonucleic acid, which was repaired upon incubation in a growth medium. After uv irradiation, these mutants resumed deoxyribonucleic acid synthesis at a normal rate, as did the parent wild-type bacteria, and formed nonseptate, multinucleate filaments. From these results we concluded that the mutants have some defect in cell division after low doses of uv irradialion, similar to the Ion/sup -/ or fil/sup +/ mutant of E. coli. The ruv locus was divided further into ruvA and ruvB with respect to nalidixic acid sensitivity and the effect of minimal agar or pantoyl lactone on survival of the uv-irradiated cell. The ruvB/sup -/ mutant was more sensitive to nalidixic acid than were ruvA- and the parent strain. There was a great increase in the surviving fraction of the uv-irradiated ruvB/sup -/ mutant when it was plated on minimal agar or L agar containing pantoyl lactone. No such increase in survival was observed in the ruvA- mutant. (auth)
- Research Organization:
- Kyushu Univ., Fukuoka
- NSA Number:
- NSA-29-018580
- OSTI ID:
- 4345426
- Journal Information:
- J. Bacteriol., v. 117, no. 2, pp. 337-344, Other Information: Orig. Receipt Date: 30-JUN-74
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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