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https://www.lightsource.ca/public/news/2024-25-q2-jul-sept/newly-discovered-protein-stops-dna-damage.php>
"Researchers from Western University have discovered a protein that has the
never-before-seen ability to stop DNA damage in its tracks. The finding could
provide the foundation for developing everything from vaccines against cancer,
to crops that can withstand the increasingly harsh growing conditions brought
on by climate change.
The researchers found the protein – called DdrC (for DNA Damage Repair Protein
C) — in a fairly common bacterium called
Deinococcus radiodurans (D.
radiodurans), which has the decidedly
uncommon ability to survive conditions
that damage DNA – for example, 5,000 to 10,000 times the radiation that would
kill a regular human cell. Lead researcher Robert Szabla says
Deinococcus
also excels in repairing DNA that has already been damaged.
“It’s as if you had a player in the NFL who plays every game without a helmet
or pads,” says Szabla, a grad student in Western’s Department of Biochemistry.
“He’d end up with a concussion and multiple broken bones every single game, but
then miraculously make a full recovery overnight in time for practice the next
day.” He and his colleagues discovered that DdrC is a key player in this repair
process.
Every cell has a DNA repair mechanism to fix damage. “With a human cell, if
there are any more than two breaks in the entire billion base pair genome, it
can’t fix itself and it dies,” he says. “But in the case of DdrC, this unique
protein helps the cell to repair hundreds of broken DNA fragments into a
coherent genome.”
Szabla and his team used the Canadian Light Source (CLS) at the University of
Saskatchewan (USask) to determine the 3D shape of the protein, from which they
then worked backwards to better understand its “superpower” to neutralize DNA
damage. “The Canadian Light Source was instrumental in that,” says Szabla.
“It’s the most powerful X-ray source in Canada.” The group’s findings were
published in the journal Nucleic Acids Research.
Turns out that DdrC scans for breaks along the DNA and when it detects one it
snaps shut – like a mousetrap. This trapping action has two key functions: “It
neutralizes it (the DNA damage), and prevents the break from getting damaged
further. And it acts like a little molecular beacon. It tells the cell ‘Hey,
over here. There’s damage. Come fix it.”
Typically, says Szabla, proteins form complicated networks that enable them to
carry out a function. DdrC appears to be something of an outlier, in that it
performs its function all on its own, without the need for other proteins. The
team was curious whether the protein might function as a “plug-in” for other
DNA repair systems. They tested this by adding it to a different bacterium:
E.
coli. “To our huge surprise, it actually made the bacterium over 40 times more
resistant to UV radiation damage,” he says. “This seems to be a rare example
where you have one protein and it really is like a standalone machine.”"
Via
Fix the News:
https://fixthenews.com/cannot-be-multiplied-not-really-good/
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
