Novel ionizing radiation-sensitive mutants of Deinococcus radiodurans

Udupa, K S; O'Cain, P A; Mattimore, V; Battista, John R.

doi:10.1128/jb.176.24.7439-7446.1994

Cited by 54 publications

(44 citation statements)

References 23 publications

(18 reference statements)

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“…D. radiodurans is nonmutable by MMC, hydroxylamine, 2-aminopurine, and zebularine; only slightly sensitive to mutation by nitrous acid and EMS; and highly mutable by MNNG and 5-azacytidine (298,597). MNNG has therefore been widely used for the generation of D. radiodurans mutants (88,202,225,304,434,437,445,446,628). Compared to E. coli, D. radiodurans is equally sensitive to the lethal effects of EMS but not its mutagenic effects.…”

Section: Resistance Of D Radiodurans To Base-damaging Chemicalsmentioning

confidence: 99%

Oxidative Stress Resistance inDeinococcus radiodurans

Slade

Radman

2011

Microbiol Mol Biol Rev

660

639

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SUMMARY Deinococcus radiodurans is a robust bacterium best known for its capacity to repair massive DNA damage efficiently and accurately. It is extremely resistant to many DNA-damaging agents, including ionizing radiation and UV radiation (100 to 295 nm), desiccation, and mitomycin C, which induce oxidative damage not only to DNA but also to all cellular macromolecules via the production of reactive oxygen species. The extreme resilience of D. radiodurans to oxidative stress is imparted synergistically by an efficient protection of proteins against oxidative stress and an efficient DNA repair mechanism, enhanced by functional redundancies in both systems. D. radiodurans assets for the prevention of and recovery from oxidative stress are extensively reviewed here. Radiation- and desiccation-resistant bacteria such as D. radiodurans have substantially lower protein oxidation levels than do sensitive bacteria but have similar yields of DNA double-strand breaks. These findings challenge the concept of DNA as the primary target of radiation toxicity while advancing protein damage, and the protection of proteins against oxidative damage, as a new paradigm of radiation toxicity and survival. The protection of DNA repair and other proteins against oxidative damage is imparted by enzymatic and nonenzymatic antioxidant defense systems dominated by divalent manganese complexes. Given that oxidative stress caused by the accumulation of reactive oxygen species is associated with aging and cancer, a comprehensive outlook on D. radiodurans strategies of combating oxidative stress may open new avenues for antiaging and anticancer treatments. The study of the antioxidation protection in D. radiodurans is therefore of considerable potential interest for medicine and public health.

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Section: Resistance Of D Radiodurans To Base-damaging Chemicalsmentioning

confidence: 99%

Oxidative Stress Resistance inDeinococcus radiodurans

Slade

Radman

2011

Microbiol Mol Biol Rev

660

639

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“…5) reveals three conserved histidines that could form a catalytic triad of a novel metal-dependent enzyme, perhaps a hydrolase. The prediction of enzymatic activity of these proteins raises the possibility that they could be nucleases directly involved in DNA degradation, which begins in Deinococcus immediately after DNA damage (23,211). This protein family may be particularly amenable to experimental studies, given its expansion in B. subtilis, a model for many DNA repair studies.…”

Section: Vol 65 2001mentioning

confidence: 99%

“…RADIODURANS GENOME ANALYSISThis family is of particular interest because at least one of its members (DR0171, or IrrI [211]) appears to be associated with radiation resistance (22). About 720 proteins encoded in the D. radiodurans genome have no detectable homologs in the current databases.…”

Section: Vol 65 2001mentioning

confidence: 99%

Genome of the Extremely Radiation-Resistant Bacterium Deinococcus radiodurans Viewed from the Perspective of Comparative Genomics

Makarova

Aravind

Wolf

et al. 2001

Microbiol Mol Biol Rev

656

612

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The bacterium Deinococcus radiodurans shows remarkable resistance to a range of damage caused by ionizing radiation, desiccation, UV radiation, oxidizing agents, and electrophilic mutagens. D. radiodurans is best known for its extreme resistance to ionizing radiation; not only can it grow continuously in the presence of chronic radiation (6 kilorads/h), but also it can survive acute exposures to gamma radiation exceeding 1,500 kilorads without dying or undergoing induced mutation. These characteristics were the impetus for sequencing the genome of D. radiodurans and the ongoing development of its use for bioremediation of radioactive wastes. Although it is known that these multiple resistance phenotypes stem from efficient DNA repair processes, the mechanisms underlying these extraordinary repair capabilities remain poorly understood. In this work we present an extensive comparative sequence analysis of the Deinococcus genome. Deinococcus is the first representative with a completely sequenced genome from a distinct bacterial lineage of extremophiles, the Thermus-Deinococcus group. Phylogenetic tree analysis, combined with the identification of several synapomorphies between Thermus and Deinococcus, supports the hypothesis that it is an ancient group with no clear affinities to any of the other known bacterial lineages. Distinctive features of the Deinococcus genome as well as features shared with other free-living bacteria were revealed by comparison of its proteome to the collection of clusters of orthologous groups of proteins. Analysis of paralogs in Deinococcus has revealed several unique protein families. In addition, specific expansions of several other families including phosphatases, proteases, acyltransferases, and Nudix family pyrophosphohydrolases were detected. Genes that potentially affect DNA repair and recombination and stress responses were investigated in detail. Some proteins appear to have been horizontally transferred from eukaryotes and are not present in other bacteria. For example, three proteins homologous to plant desiccation resistance proteins were identified, and these are particularly interesting because of the correlation between desiccation and radiation resistance. Compared to other bacteria, the D. radiodurans genome is enriched in repetitive sequences, namely, IS-like transposons and small intergenic repeats. In combination, these observations suggest that several different biological mechanisms contribute to the multiple DNA repair-dependent phenotypes of this organism

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“…The mechanisms of this resistance are unclear. Our objectives in this paper are to report on predicted highly expressed genes (PHX) and putative alien (PA) genes (see below for formal definitions) and their implications how these genes may help guide research into understanding DEIRA survival through periods of extended ionizing damage and desiccation (2)(3)(4)(5)(6). The complete lists of PHX and PA genes in DEIRA are presented in our ftp site, ftp:͞͞gnomic.stanford.edu͞pub͞ highlyexpressed.…”

mentioning

confidence: 99%

Predicted highly expressed and putative alien genes of Deinococcus radiodurans and implications for resistance to ionizing radiation damage

Karlin

Mrázek

2001

Proc. Natl. Acad. Sci. U.S.A.

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Predicted highly expressed (PHX) and putative alien genes determined by codon usages are characterized in the genome of Deinococcus radiodurans (strain R1). Deinococcus radiodurans (DEIRA) can survive very high doses of ionizing radiation that are lethal to virtually all other organisms. It has been argued that DEIRA is endowed with enhanced repair systems that provide protection and stability. However, predicted expression levels of DNA repair proteins with the exception of RecA tend to be low and do not distinguish DEIRA from other prokaryotes. In this paper, the capability of DEIRA to resist extreme doses of ionizing and UV radiation is attributed to an unusually high number of PHX chaperone͞degradation, protease, and detoxification genes. Explicitly, compared with all current complete prokaryotic genomes, DEIRA contains the greatest number of PHX detoxification and protease proteins. Other sources of environmental protection against severe conditions of UV radiation, desiccation, and thermal effects for DEIRA are the several S-layer (surface structure) PHX proteins. The top PHX gene of DEIRA is the multifunctional tricarboxylic acid (TCA) gene aconitase, which, apart from its role in respiration, also alerts the cell to oxidative damage.

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Novel ionizing radiation-sensitive mutants of Deinococcus radiodurans

Cited by 54 publications

References 23 publications

Oxidative Stress Resistance inDeinococcus radiodurans

Oxidative Stress Resistance inDeinococcus radiodurans

Genome of the Extremely Radiation-Resistant Bacterium Deinococcus radiodurans Viewed from the Perspective of Comparative Genomics

Predicted highly expressed and putative alien genes of Deinococcus radiodurans and implications for resistance to ionizing radiation damage

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