Amazing stuff! This is an article based on past research. This is a review article of a review article by one of the leading researchers in this field as it appears.
The secret sauce seems to be manganese.
"For a human, experiencing a mere five grays (Gy) of ionizing radiation for just a few minutes can be lethal. But the bacterium Deinococcus radiodurans is made of tougher stuff. In liquid culture conditions, it can survive an acute blast of up to 25,000Gy and under chronic gamma radiation exposure (60Gy per hour), it not only survives, but thrives, continuing to grow and multiply. ...
It was discovered ... at an agricultural research station in Oregon. In the 1950s, researchers at the station were experimenting with using ionizing radiation to sterilize canned food. To their dismay, some of their heavily-irradiated corned beef still contained living microbes—they cultured the microbes and discovered D. radiodurans.
Over the following decades, scientists tried to identify the mechanisms underlying the microbe’s extreme radiation resistance. They found that the microbe could repair many more double-strand breaks within its DNA than other organisms. However, when its genome was sequenced in the early 2000s, the genes coding for DNA repair enzymes were surprisingly similar to other bacterial species, indicating that specialized repair enzymes probably weren’t responsible for the microbe’s remarkable hardiness. ...
“One of the key findings from that large body of work was the high dependence of these microorganisms on manganese,” ... Manganese can function as powerful antioxidant, which could help protect intracellular molecules from the reactive oxygen species (ROS) generated when ionizing radiation, such as gamma rays, interacts with water molecules in the cell. But there was more to the story than just manganese. ...
“We were observing the emergent antioxidant’s chemistry: three components where they do much more together—much, much more together—than individually,” ... In test tubes, mixing these three components—manganese, orthophosphate, and small peptides approximately 10–20 amino acids long—preserved the function of proteins and increased the survival of human cells in the face of high-dose radiation. ..."
From the abstract:
"The family Deinococcaceae exhibits exceptional radiation resistance and possesses all the necessary traits for surviving in radiation-exposed environments. Their survival strategy involves the coupling of metabolic and DNA repair functions, resulting in an extraordinarily efficient homologous repair of DNA double-strand breaks (DSBs) caused by radiation or desiccation. The keys to their survival lie in the hyperaccumulation of manganous (Mn2+)-metabolite antioxidants that protect their DNA repair proteins under extreme oxidative stress and the persistent structural linkage by Holliday junctions of their multiple genome copies per cell that facilitates DSB repair.
This coupling of metabolic and DNA repair functions has made polyploid Deinococcus bacteria a useful tool in environmental biotechnology, radiobiology, aging, and planetary protection.
The review highlights the groundbreaking contributions of the late Robert G.E. Murray to the field of Deinococcus research and the emergent paradigm-shifting discoveries that revolutionized our understanding of radiation survivability and oxidative stress defense, demonstrating that the proteome, rather than the genome, is the primary target responsible for survivability. These discoveries have led to the commercial development of irradiated vaccines using Deinococcus Mn-peptide antioxidants and have significant implications for various fields."
The scientific revolution that unraveled the astonishing DNA repair capacity of the Deinococcaceae: 40 years on (open access)
Fig. 3. Sequential recombinational pathways for double-strand break (DSB) repair in Deinococcus radiodurans that benefit from persistent linkage by Holliday junctions.
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