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Researcher: DNA folding in Archaea very similar to complex cells. “It just blows my mind.”

Archaea DNA wrapped around histones/Francesca Mattiroli

Archaea are thought to be about 3.8 billion years old. From ScienceDaily:

By studying the 3-D structure of proteins bound to DNA in microbes called archaea, researchers have turned up surprising similarities to DNA packing in more complicated organisms. “If you look at the nitty gritty, it’s identical,” says Howard Hughes Medical Institute Investigator Karolin Luger, a structural biologist and biochemist at the University of Colorado Boulder. “It just blows my mind.”

The archaeal DNA folding, reported August 10 in Science, hints at the evolutionary origins of genome folding, a process that involves bending DNA and one that is remarkably conserved across all eukaryotes (organisms that have a defined nucleus surrounded by a membrane). Like Eukarya and Bacteria, Archaea represents one of the three domains of life. But Archaea is thought to include the closest living relatives to an ancient ancestor that first hit on the idea of folding DNA.

The results suggest that the archaeal DNA folding is an early prototype of the eukaryotic nucleosome. “I don’t think there’s any doubt that it’s ancestral,” Reeve says.

Still, many questions remain. Luger says she’d like to look for the missing link — a nucleosome-like structure that bridges the gap between the simple archaeal fold and the elaborate nucleosome found in eukaryotes, which can pack a huge amount of DNA into a small space and regulate gene behavior in many ways. “How did we get from here to there?” she asks. Paper. (paywall) – Francesca Mattiroli et al. Structure of histone-based chromatin in Archaea. Science, 2017 DOI: 10.1126/science.aaj1849 More.

If it’s that old, we run into the same “earlier than thought” problem we have often encountered: How did it get to be so complex so early if success depended entirely on random outcomes?

A friend observes that a mechanism complex organisms need is found long before they exist as well. It certainly sounds like a program.

See also: Advanced multicellular plant-like fossils appeared “much earlier than thought”

Earliest animals with true body cavities found at 30 mya earlier than thought


Stasis: Life goes on but evolution does not happen

from the article:
Archaea wrap their DNA (yellow) around proteins called histones (blue), shown above in a 3-D representation. The wrapped structure bears an uncanny resemblance to the eukaryotic nucleosome, a bundle of eight histone proteins with DNA spooled around it. But unlike eukaryotes, archaea wind their DNA around just one histone protein, and form a long, twisting structure called a superhelix.
The wrapping (and unwrapping) of DNA around histones in eukaryotic nucleosome is the result of signaling activated on the histone tails using the histone CODE. For a computer programmer like me, I see it as equivalent to using the the command "OPEN FILE" prior to reading the file and the command "CLOSE FILE" when finished. The thought of an Archaea operating system function evolving into an Eukaryotic operating system function by chance is kind of comical to this deplorable non-scientist. awstar
Luger says she’d like to look for the missing link
Missing link, you say? Just one? PaV
[...] researchers have turned up surprising similarities [...] When are these folks going to stop being surprised by things they see in biology that contradict their poor expectations? :)
> But at least we can laugh at their lunacy without compunction. We're laughing with them. For sure. Mung
Back in the old Evolution groove again, polistra : 'Gee ! Isn't Evolution marvellous ! It always manages to surprise us!' If I want cheering up, I come to this site, because your opponents absolutely force you to be very witty. Such is their folly, you're not even trying to be witty, but you could lay out the facts in your sleep, and they would sound highly comical. That's what gets me. It reminds me of the saying of Truman : 'I never did give anybody hell. I just told the truth and they thought it was hell.' Except that they are so obstinately blind to their own folly that, of course, they are not really aware that you are giving them hell by showing them the truth. But at least we can laugh at their lunacy without compunction. Axel
This sort of thing has happened thousands of times now. Thought to be recent, turns out to be ancient. Much older than thought. Much more widespread than thought. Believed extinct, found to be common. Scientists should pay attention to Nature instead of the voices in their heads. polistra
This is exactly what we would expect to see if evolution is true. But if Eukaryotes were formed by gobbling up some other form of life, in what sense is this feature ancestral? By the way, aren't the exact same proteins/enzymes involved? If so, why why would anyone be astounded? Mung

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