Inducible DNA polymerase I synthesis in a UV hyper-resistant mutant of Escherichia coli

doi:10.1016/0165-7992(87)90035-2

Mutation Research Letters

Volume 190, Issue 2, February 1987, Pages 77-81

https://doi.org/10.1016/0165-7992(87)90035-2 Get rights and content

Abstract

A mutant of Escherichia coli which is more resistant to shortwave UV light than its wild-type parent strain and which can synthesise DNA polymerase I constitutively has been further analysed. It carries two mutational alleles which are located about 1.5 min apart and cotransducible by P1 with the argHlocus. The two mutational alleles have been segregated and their analysis shows that one of them is responsible for UV hyper-resistance whereas the other mutation confers UV sensitivity.

Recombinant plasmids carrying various sections of the polA regulatory region, linked to a galK gene, were introduced into the mutant strains. Analysis of galactokinase shows that the enzyme activity in the UV hyper-resistant mutant is increased. The results suggest that the synthesis of DNA polymerase I in E. coli is inducible.

References (11)

R.S. Fuller et al.
The dnaA protein complex with the Escherichia coli chromosomal replication origin (oriC) and other DNA sites
Cell
(1984)
B. Glickman
The role of DNA polymerase I in pyrimidine dimer excision and repair replication in Escherichia coli K12 following ultraviolet irradiation
Biochim. Biophys. Acta
(1974)
C.M. Joyce et al.
Nucleotide sequence of the Escherichia coli polA gene and primary structure of DNA polymerase I
J. Biol. Chem.
(1982)
S.I. Ahmad et al.
Isolation and characterization of a mutant of Escherichia coli K12 synthesising DNA polymerase I and endonuclease I constitutively
J. Gen. Microbiol.
(1980)
B.J. Bachmann et al.
Linkage map of Escherichia coli K12
Microbiol. Rev.
(1980)

There are more references available in the full text version of this article.

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Isolation and analysis of UV and radio-resistant bacteria from Chernobyl
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The accident at the Chernobyl nuclear power station in 1986 led to the dispersal of large amounts of a variety of radioactive materials, most importantly uranium, plutonium, ¹³⁷Cs, ¹³¹I and ⁹⁰Sr, over very large distances estimated to reach as far as Sweden, Norway, Turkey and possibly the USA. As a consequence, the soil on which the radioactive materials fell was contaminated and the degree of contamination varied with distance from the station, the direction and strength of the wind and the amount of atmospheric scavenging by rainfall at that time. Some of the radioactive materials have left a significant impact on mankind in the form of chromosomal aberrations including trisomy, various forms of cancers and death, whilst others are still in the ground where they will remain for a prolonged period to continue to exert their effects. Likewise, microbes living in the soil and exposed to radioactive materials may have been affected in a number of ways; some perished, and others survived due to the acquisition of advantageous mutation. Six years after the accident, soil samples contaminated with different levels of radioactivity were obtained from five regions within a 30 km radius of the nuclear power plant. From these soil samples spore-forming bacilli were isolated, quantified, identified and tested for resistance to X-rays, UVC and 4-nitroquinoline 1-oxide (4NQO). As a control, spore-forming bacilli were obtained from ‘Zeleny mys’ (an area 50 km south-east of the power station and emitting basal levels of radioactivity). A mutant of Escherichia coli hyper-resistant to a variety of DNA-damaging agents and its parent strain were also included in the study. Analysis of results reveals that a proportion of isolates of the same species from near the power station and the E. coli mutant SA236 were more resistant to X-rays, UVC and 4NQO compared with isolates from the control site and the E. coli parent strain, KL14, respectively.
Biochemical and mutational studies of the 5'-3' exonuclease of DNA polymerase I of Escherichia coli
1997, Journal of Molecular Biology
In order to improve our understanding of the 5′-3′ exonuclease reaction catalyzed by Escherichia coli DNA polymerase I, we have constructed expression plasmids and developed purification methods for whole DNA polymerase I and its 5′-3′ exonuclease domain that allow the production of large quantities of highly purified material suitable for biophysical and other studies. We have studied the enzymatic properties of the 5′-3′ exonuclease, both as an isolated domain and in the context of the whole polymerase, using a variety of model oligonucleotides to explore the enzyme-substrate interaction. The 5′-3′ exonuclease is known to be a structure-specific nuclease that cleaves a 5′ displaced strand at the junction between single-stranded and duplex regions. Since the isolated domain shows the same structure specificity as the whole polymerase, the correct geometry of substrate binding is achieved without the assistance of the polymerase domain. The 5′-3′ exonuclease reaction has a strict requirement for a free 5′ end on the displaced strand; however, the upstream template and primer strands are dispensable. Site-directed mutagenesis of the ten carboxylate residues that are highly conserved among bacterial and bacteriophage 5′-3′ exonucleases indicates that nine of them are important in the reaction. This finding is discussed in relation to structural and mutational data for related 5′ nucleases.
A mutant of Escherichia coli hyper-resistant to a number of DNA damaging agents: Location of the mutational site
1996, Journal of Photochemistry and Photobiology B: Biology
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1998, Annual Review of Microbiology
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1997, Russian Journal of Genetics
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Mutation Research Letters

Abstract

References (11)

The dnaA protein complex with the Escherichia coli chromosomal replication origin (oriC) and other DNA sites

Cell

The role of DNA polymerase I in pyrimidine dimer excision and repair replication in Escherichia coli K12 following ultraviolet irradiation

Biochim. Biophys. Acta

Nucleotide sequence of the Escherichia coli polA gene and primary structure of DNA polymerase I

J. Biol. Chem.

Isolation and characterization of a mutant of Escherichia coli K12 synthesising DNA polymerase I and endonuclease I constitutively

J. Gen. Microbiol.

Linkage map of Escherichia coli K12

Microbiol. Rev.

Cited by (9)

Isolation and analysis of UV and radio-resistant bacteria from Chernobyl

Biochemical and mutational studies of the 5'-3' exonuclease of DNA polymerase I of Escherichia coli

A mutant of Escherichia coli hyper-resistant to a number of DNA damaging agents: Location of the mutational site

Thymine metabolism and thymineless death in prokaryotes and eukaryotes

Plasmid Hyperrecombination Is Typical for Escherichia coli Hyperresistant Strains

Plasmid hyperrecombination is typical for escherichia coü hyperresistant strains

Research letterInducible DNA polymerase I synthesis in a UV hyper-resistant mutant of Escherichia coli

Abstract

Cell

Biochim. Biophys. Acta

J. Biol. Chem.

Isolation and characterization of a mutant of Escherichia coli K12 synthesising DNA polymerase I and endonuclease I constitutively

J. Gen. Microbiol.

Linkage map of Escherichia coli K12

Microbiol. Rev.

Research letter
Inducible DNA polymerase I synthesis in a UV hyper-resistant mutant of Escherichia coli