Part of the resistance of D. radiodurans to high doses of UV radiation due to the protection of pro

- Grouped in Diplococcus in the early stages and tetrads in advanced stages.
The cell wall is special D.radiodurans. Although it looks a gram positive gram negative because it has several layers of peptidoglycan on. It also has some specific lipids. This wall gives a first radiation protection and other extreme conditions. [5]
Figure rsc box 3: Structure of the cell wall of D. radiodurans [5]. But mostly rsc box known for the ability to survive in extremely high doses of radiation. It is 200 times more resistant to ionizing radiation rsc box and 20 times more resistant to ultraviolet radiation (UV) that Escherichia coli [3]. In humans, a dose of 10Gy in 5 (Grey) is enough to kill a person; D. radiodurans however reluctant to 15000Gy [7]. One of the applications of D. radiodurans, thanks to its resistance to radiation could be bioremediation of toxic radioactive waste produced as many problems, such as having them deposited radioactive cemeteries. rsc box To achieve that degrade waste, you could insert genes from other bacteria transform heavy metals rsc box less toxic and less soluble forms [8]. Some studies rsc box have shown that carotenoids or specific coenzymes D. radiodurans rsc box have antioxidant effects on cardiomyocytes and delay the onset of disease in rats neurodegeneretives. Studying what effect humans have on preventing the onset of diseases such as Alzheimer's or Parkinson's disease, delaying aging and new cures for cancer. [1] This video shows some of the characteristics of D. radiodurans bacteria and other potential applications. [9]
Figure 4: Type pirimidínics dimers induced by UV [10]. On the one hand, induces the appearance of photoproduct bipirimidínics (BPPs) as pirimidínics of Cyclobutane dimers (DPCs) and photoproduct of pirimidina- (6-4) -pirimidona (6-4 PPs) [1] (Figure 4). The nitrogenous base is more likely rsc box to form thymine dimers. As has been observed rsc box that the percentage of AT D radiodurans genome is lower compared to the GC (67%), the number of dimers decreases formats; thus being a preventive measure against UV radiation [11]. In contrast, the human GC content is 41% [12]. This also indicates that D. radiodurans is resistant to UV radiation than we humans.
Furthermore, UV radiation induces the formation of reactive oxygen species (ROS): hydroxyl radicals, superoxide radicals and hydrogen peroxide, which oxidize macromolecules. The oxidation of proteins affects their catalytic activity and the basic functions rsc box of the cell, which may end up dying. [1]
UV light also causes DNA fragmentation. The double strand breaks (DSB, English rsc box Double Strand Breaks) arise when the replication fork collapse by the presence of dimers that impede the advancement of DNA polymerase acts or when the system repair eliminating two dimers (BPPs English Bipyrimidine Photoproducts) located very close to the opposite chains. Also occur when the dose of UV radiation are very high [1]. SOURCE RESISTANCE rsc box
Part of the resistance of D. radiodurans to high doses of UV radiation due to the protection of proteins rsc box to prevent oxidative damage. Otherwise, although the majority share of the mechanisms of DNA repair with other bacteria in D. radiodurans efficiency is higher [1] [3]. However, rsc box it is unclear which of the two aspects most influence on the resistance to UV radiation.
Protection against oxidation of certain proteins, such as RNA polymerase elongation factors and to allow rapid protein synthesis and recovery of degraded all cellular functions after irradiation. Some proteins are less prone to oxidation because they have amino acids may be rusty inside so they are inaccessible by ROS [1] [3] [5]. It also protects DNA from oxidation by ROS due to the packaging of the genome [1].
"Cleaning" cellular macromolecules removing oxidized to prevent nucleotides, nucleosides and damaged proteins accumulate in the cytoplasm. D. radiodurans expels most damaged nucleotides outside rsc box and transforms the remaining preventing their re-entry into the new DNA synthesis. It also degrades damaged proteins [5] [3] [1] (Table 1).
Antioxidant molecules that neutralize ROS. Can be: enzymatic 2 catalase, superoxide dismutase and various peroxidases [3]. No enzyme: carotenoid rsc box molecules resulting from the proteolytic activity and nucleolítica (nucleosides, amino acids and peptides) rsc box complex of divalent