Inducible error-prone repair in Escherichia coli
A hypothesis that ultraviolet-induced mutagenesis arises from the induction of an error-prone mode of postreplication repair that requires the exrA$sup +$ recA$sup +$ genotype has been tested with alkaline sucrose gradient centrifugation coupled with assays of fixation determined by loss of photoreversibility. The inhibitor of protein synthesis, chloramphenicol, added before irradiation, prevented a small amount of postreplication repair and completely eliminated mutation fixation in E. coli WP2/sub s/ uvrA. However, chloramphenicol did not affect strand joining: (a) in uvrA bacteria allowed 20 min of growth between irradiation and antibiotic treatment; (b) in nonmutable uvrA exrA bacteria; and (c) in uvrA tif bacteria grown at 42$sup 0$ for 70 min before irradiation. These observations indicate that an inducible product is involved in a fraction of postreplication repair and is responsible for induced mutagenesis. (auth)
- Research Organization:
- Brookhaven National Lab., Upton, NY
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-33-020477
- OSTI ID:
- 4087154
- Journal Information:
- Proc. Natl. Acad. Sci. U.S.A., v. 72, no. 7, pp. 2753-2757, Journal Name: Proc. Natl. Acad. Sci. U.S.A., v. 72, no. 7, pp. 2753-2757; ISSN PNASA
- Country of Publication:
- United States
- Language:
- English
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