title: Effect of a recD mutation on DNA damage resistance and transformation in Deinococcus radiodurans.
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.
authors.affiliation: Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Servinsky
authors.forename: Douglas A
authors.initials: DA
authors.lastname: Julin
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D015139:Blotting, Southern; D004249:DNA Damage; D004269:DNA, Bacterial / Q000235:genetics; D034301:Deinococcus / Q000187:drug effects / Q000235:genetics* / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D043211:Exodeoxyribonuclease V / Q000235:genetics* / Q000378:metabolism; D005720:Gamma Rays; D005816:Genetic Complementation Test; D006861:Hydrogen Peroxide / Q000494:pharmacology; D050296:Microbial Viability / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects; D009154:Mutation; D014169:Transformation, Bacterial; D014466:Ultraviolet Rays
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D006861:Hydrogen Peroxide; D043211:Exodeoxyribonuclease V