scholarly journals The IrrE Protein of Deinococcus radiodurans R1 Is a Novel Regulator of recA Expression

2002 ◽  
Vol 184 (22) ◽  
pp. 6216-6224 ◽  
Author(s):  
Ashlee M. Earl ◽  
Michael M. Mohundro ◽  
I. Saira Mian ◽  
John R. Battista
Keyword(s):  
Dna Damage ◽  
Ionizing Radiation ◽  
Radiation Resistance ◽  
Deinococcus Radiodurans ◽  
Genomic Library ◽  
Uv Light ◽  
Regulatory Protein ◽  
Chromosome I ◽  
Ionizing Radiation Resistance ◽  
Deinococcus Radiodurans R1

ABSTRACT IRS24 is a DNA damage-sensitive strain of Deinococcus radiodurans strain 302 carrying a mutation in an uncharacterized locus designated irrE. Five overlapping cosmids capable of restoring ionizing radiation resistance to IRS24 were isolated from a genomic library. The ends of each cloned insert were sequenced, and these sequences were used to localize irrE to a 970-bp region on chromosome I of D. radiodurans R1. The irrE gene corresponds to coding sequence DR0167 in the R1 genome. The irrE gene encodes a 35,000-Da protein that has no similarity to any previously characterized peptide. The irrE locus of R1 was also inactivated by transposon mutagenesis, and this strain was sensitive to ionizing radiation, UV light, and mitomycin C. Preliminary findings indicate that IrrE is a novel regulatory protein that stimulates transcription of the recA gene following exposure to ionizing radiation.

Bacterial sensitivity to UV light as a model for ionizing radiation resistance

1993 ◽  
Vol 18 (2) ◽  
pp. 127-136 ◽  
Author(s):  
Andrew A. Arrange ◽  
Tommy J. Phelps ◽  
Robert E. Benoit ◽  
Anthony V. Palumbo ◽  
David C. White
Keyword(s):  
Ionizing Radiation ◽  
Radiation Resistance ◽  
Uv Light ◽  
Bacterial Sensitivity ◽  
Ionizing Radiation Resistance

scholarly journals Effect of a recD Mutation on DNA Damage Resistance and Transformation in Deinococcus radiodurans

2007 ◽  
Vol 189 (14) ◽  
pp. 5101-5107 ◽  
Author(s):  
Matthew D. Servinsky ◽  
Douglas A. Julin
Keyword(s):  
Hydrogen Peroxide ◽  
Dna Damage ◽  
Ionizing Radiation ◽  
Mitomycin C ◽  
Deinococcus Radiodurans ◽  
Uv Light ◽  
Gene Encoding ◽  
Significant Similarity ◽  
Damage Repair ◽  
Recbcd Enzyme

ABSTRACT The bacterium Deinococcus radiodurans is resistant to extremely high levels of DNA-damaging agents such as UV light, ionizing radiation, and chemicals such as hydrogen peroxide and mitomycin C. The organism is able to repair large numbers of double-strand breaks caused by ionizing radiation, in spite of the lack of the RecBCD enzyme, which is essential for double-strand DNA break repair in Escherichia coli and many other bacteria. The D. radiodurans genome sequence indicates that the organism lacks recB and recC genes, but there is a gene encoding a protein with significant similarity to the RecD protein of E. coli and other bacteria. We have generated D. radiodurans strains with a disruption or deletion of the recD gene. The recD mutants are more sensitive than wild-type cells to irradiation with gamma rays and UV light and to treatment with hydrogen peroxide, but they are not sensitive to treatment with mitomycin C and methyl methanesulfonate. The recD mutants also show greater efficiency of transformation by exogenous homologous DNA. These results are the first indication that the D. radiodurans RecD protein has a role in DNA damage repair and/or homologous recombination in the organism.

scholarly journals Directed Evolution of Ionizing Radiation Resistance in Escherichia coli

2009 ◽  
Vol 191 (16) ◽  
pp. 5240-5252 ◽  
Author(s):  
Dennis R. Harris ◽  
Steve V. Pollock ◽  
Elizabeth A. Wood ◽  
Reece J. Goiffon ◽  
Audrey J. Klingele ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Ionizing Radiation ◽  
Directed Evolution ◽  
Radiation Resistance ◽  
Bacterial Species ◽  
Repair System ◽  
Multiple Alleles ◽  
Evolutionary Pathways ◽  
K 12 ◽  
Ionizing Radiation Resistance

ABSTRACT We have generated extreme ionizing radiation resistance in a relatively sensitive bacterial species, Escherichia coli, by directed evolution. Four populations of Escherichia coli K-12 were derived independently from strain MG1655, with each specifically adapted to survive exposure to high doses of ionizing radiation. D37 values for strains isolated from two of the populations approached that exhibited by Deinococcus radiodurans. Complete genomic sequencing was carried out on nine purified strains derived from these populations. Clear mutational patterns were observed that both pointed to key underlying mechanisms and guided further characterization of the strains. In these evolved populations, passive genomic protection is not in evidence. Instead, enhanced recombinational DNA repair makes a prominent but probably not exclusive contribution to genome reconstitution. Multiple genes, multiple alleles of some genes, multiple mechanisms, and multiple evolutionary pathways all play a role in the evolutionary acquisition of extreme radiation resistance. Several mutations in the recA gene and a deletion of the e14 prophage both demonstrably contribute to and partially explain the new phenotype. Mutations in additional components of the bacterial recombinational repair system and the replication restart primosome are also prominent, as are mutations in genes involved in cell division, protein turnover, and glutamate transport. At least some evolutionary pathways to extreme radiation resistance are constrained by the temporally ordered appearance of specific alleles.

scholarly journals A variant of the Escherichia coli anaerobic transcription factor FNR exhibiting diminished promoter activation function enhances ionizing radiation resistance

PLoS ONE ◽  
2019 ◽  
Vol 14 (1) ◽  
pp. e0199482 ◽  
Author(s):  
Steven T. Bruckbauer ◽  
Joseph D. Trimarco ◽  
Camille Henry ◽  
Elizabeth A. Wood ◽  
John R. Battista ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Transcription Factor ◽  
Ionizing Radiation ◽  
Radiation Resistance ◽  
Activation Function ◽  
Promoter Activation ◽  
Ionizing Radiation Resistance

RadA: A protein involved in DNA damage repair processes of Deinococcus radiodurans R1

2006 ◽  
Vol 51 (24) ◽  
pp. 2993-2999 ◽  
Author(s):  
Qing Zhou ◽  
Xinjue Zhang ◽  
Hong Xu ◽  
Bujin Xu ◽  
Yuejin Hua
Keyword(s):  
Dna Damage ◽  
Deinococcus Radiodurans ◽  
Dna Damage Repair ◽  
Repair Processes ◽  
Damage Repair ◽  
Deinococcus Radiodurans R1
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