Reassembly of shattered chromosomes in Deinococcus radiodurans

  title={Reassembly of shattered chromosomes in Deinococcus radiodurans},
  author={Ksenija Zahradka and Dea Slade and Adriana Bailone and Suzanne Sommer and Dietrich Averbeck and Mirjana Petranović and Ariel B. Lindner and Miroslav Radman},
Dehydration or desiccation is one of the most frequent and severe challenges to living cells. [] Key Method In ESDSA, chromosomal fragments with overlapping homologies are used both as primers and as templates for massive synthesis of complementary single strands, as occurs in a single-round multiplex polymerase chain reaction. This synthesis depends on DNA polymerase I and incorporates more nucleotides than does normal replication in intact cells. Newly synthesized complementary single-stranded extensions…

Nucleoid organization in the radioresistant bacterium Deinococcus radiodurans

The organization of chromosome 1 by localization of three chromosomal loci including oriC, Ter and a locus located in its left arm is investigated, demonstrating that the 4–10 copies of chromosomes 1 per cell are dispersed within the nucleoid before irradiation, indicating that the chromosome copies are not prealigned.

Characterization of gross genome rearrangements in Deinococcus radiodurans recA mutants

The detected rearrangements consisted of large deletions in chromosome II in all the sequenced recA isolates, and the mechanism behind these deletions clearly differs from the classical SSA; it utilized short (4–11 bp) repeats as opposed to insertion sequences or other long repeats.

Biochemical and biological characterization of three DNA repair enzymes in Deinococcus radiodurans

The D. radiodurans recJ gene (encoded by locus DR1126) cannot be completely removed from the chromosome, indicating the essential role of RecJ in cell growth, and RecJ is the exonuclease in the RecF pathway, which is suggested to function at the initiation step in DSB repair in the absence of RecBCD.

The Family X DNA Polymerase from Deinococcus radiodurans Adopts a Non-standard Extended Conformation

The overall conformation and the presence of non standard residues in the active site of the polymerase X domain makes PolXDr the founding member of a novel class of polymerases involved in DNA repair but whose detailed mode of action still remains enigmatic.

Lesion Bypass Activity of DNA Polymerase A from the Extremely Radioresistant Organism Deinococcus radiodurans*

The DNA polymerase domain of PolA is expressed and characterized for the first time in vitro and an enzyme modulator function of Mn(II) is suggested, parallel reports that D. radiodurans accumulates intracellular Mn(ii) in cases of irradiation and that the level of irradiated protection correlates with Mn( II) concentrations.

DdrB Protein, an Alternative Deinococcus radiodurans SSB Induced by Ionizing Radiation*

The results establish DdrB as the prototype of a new bacterial SSB family and the induction of an alternative and quite novel SSB following irradiation has potentially broad significance for the organization of genome reconstitution functions.

Investigating Deinococcus radiodurans RecA protein filament formation on double-stranded DNA by a real-time single-molecule approach.

Single-molecule tethered particle motion experiments are developed to study the assembly dynamics of RecA proteins on individual duplex DNA molecules by observing changes in DNA tether length resulting from RecA binding, demonstrating that DrRecA nucleation on double-stranded DNA is much faster than that of Escherichia coli RecA protein (EcRecA), but the extension is slower.

Biological characterization of RecD mutants in Deinococcus radiodurans

This finding is the first published result of a member of the recD-like sub-family of proteins that suggests role in DNA Repair through some form of recombinational repair.



Ringlike Structure of the Deinococcus radiodurans Genome: A Key to Radioresistance?

It is proposed that, because of restricted diffusion within the tightly packed and laterally ordered DNA toroids, radiation-generated free DNA ends are held together, which may facilitate template-independent yet error-free joining of DNA breaks.

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

An extensive comparative sequence analysis of the Deinococcus genome suggests that several different biological mechanisms contribute to the multiple DNA repair-dependent phenotypes of this organism.

Preserving Genome Integrity: The DdrA Protein of Deinococcus radiodurans R1

It is proposed that DR0423 is part of a DNA end-protection system that helps to preserve genome integrity following exposure to ionizing radiation and is designated as DNA damage response A protein.

Genome sequence of the radioresistant bacterium Deinococcus radiodurans R1.

Deinococcus radiodurans represents an organism in which all systems for DNA repair, DNA damage export, desiccation and starvation recovery, and genetic redundancy are present in one cell.

Whole-genome shotgun optical mapping of Deinococcus radiodurans.

A whole-genome restriction map of Deinococcus radiodurans, a radiation-resistant bacterium able to survive up to 15,000 grays of ionizing radiation, was constructed without using DNA libraries, the

An alternative pathway of recombination of chromosomal fragments precedes recA-dependent recombination in the radioresistant bacterium Deinococcus radiodurans

Structures consistent with the hypothesis that DNA repair occurring immediately postirradiation is by a recA-independent single-strand annealing reaction and may be a preparatory step for further DNA repair in wild-type D. radiodurans were found.

Deinococcus radiodurans — the consummate survivor

It seems that D. radiodurans uses mechanisms that limit DNA degradation and that restrict the diffusion of DNA fragments that are produced following irradiation, to preserve genetic integrity.

Radioresistance of Deinococcus radiodurans: functions necessary to survive ionizing radiation are also necessary to survive prolonged desiccation

The evidence presented suggests that D. radiodurans' ionizing radiation resistance is incidental, a consequence of this organism's adaptation to a common physiological stress, dehydration.

Quantification of RecA protein in Deinococcus radiodurans reveals involvement of RecA, but not LexA, in its regulation

It is suggested that RecA may be involved in regulating its own expression, possibly by stimulating proteolytic modification of other regulatory proteins.

Mismatch repair ensures fidelity of replication and recombination in the radioresistant organism Deinococcus radiodurans

Cells devoid of MutS1 or MutL proteins were as resistant to γ-rays, mitomycin C and UV-irradiation as wild-type bacteria, suggesting that the mismatch repair system is not essential for the reconstitution of a functional genome after DNA damage.