Exonuclease III and the catalase hydroperoxidase II in Escherichia coli are both regulated by the katF gene product
The levels of both exonuclease III (exo III, product of xthA) and hydroperoxidase II (HP-II, product of katE) activity in Escherichia coli were influenced by a functional katF gene. The katF gene product is also necessary for synthesis of HP-II. Mutations in either katF or xthA, but not katE, result in sensitivity to H/sub 2/O/sub 2/ and near-UV (300-400 nm) radiation. Exo III, encoded by the xthA locus, recognizes and removes nucleoside 5'-monophosphates near apurinic and apyrimidinic sites in damaged DNA. Extracts of katF mutant strains had little detectable exo III activity. When a katF+ plasmid was introduced into the katF mutant, exo III activity exceeded wild-type levels. We propose that the katF gene is a trans-acting positive regulator of exo III and HP-II enzymes, both of which are involved in cellular recovery from oxidative damage.
- Research Organization:
- Univ. of Missouri, Columbia (USA)
- OSTI ID:
- 6021720
- Journal Information:
- Proc. Natl. Acad. Sci. U.S.A.; (United States), Vol. 86:9
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ESCHERICHIA COLI
GENE REGULATION
HYDROGEN PEROXIDE
TOXICITY
NUCLEASES
GENES
PEROXIDASES
DNA REPAIR
ENZYME ACTIVITY
GENETIC RADIATION EFFECTS
MUTATIONS
NUCLEOTIDES
PLASMIDS
ULTRAVIOLET RADIATION
BACTERIA
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CELL CONSTITUENTS
ELECTROMAGNETIC RADIATION
ENZYMES
ESTERASES
GENETIC EFFECTS
HYDROGEN COMPOUNDS
HYDROLASES
MICROORGANISMS
ORGANIC COMPOUNDS
OXIDOREDUCTASES
OXYGEN COMPOUNDS
PEROXIDES
PHOSPHODIESTERASES
RADIATION EFFECTS
RADIATIONS
RECOVERY
REPAIR
560300* - Chemicals Metabolism & Toxicology
560130 - Radiation Effects on Microorganisms