Theoretical origin of life: more lab designs for RNA (Introduction)

by David Turell , Wednesday, September 14, 2022, 21:58 (590 days ago) @ David Turell

Intelligent design at work in the lab:

https://phys.org/news/2022-09-life-rna-pocket.html

"As to the primordial peptide-bond-making machine, they discovered that it's still present in virtually every cell of all living organisms, from bacteria to plants and animals, including ourselves.

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"'We discovered a surprising feature in the structure of this protein-making machine," says Dr. Anat Bashan, a senior staff scientist in Yonath's lab in Weizmann's Chemical and Structural Biology Department. "The ribosome is an enormous macromolecule that is not at all symmetrical; at its heart, it contains two semisymmetrical elements joined together to form a pocket."

"Yonath says that they "were particularly struck by the fact that this pocket is found in the ribosomes of all organisms. And this is where all the action takes place—it's where all peptide bonds that create the chain of linked amino acids making up a protein are formed. That's why this basic machinery seems to have persisted unchanged throughout evolution."

"Meet the protoribosome: That's what the scientists call this pocket-like structure. They hypothesized that the protoribosome is the ancestor of all modern ribosomes, an ancient machine dating back to the prelife period. In comparison to the size of the cell, the protoribosome is rather small. It consists of RNA molecules comprising some 120 nucleotides, about 60 for each of its two semisymmetrical components, which accounts for less than 5 percent of the modern ribosome's dimensions: some 4,500 nucleotides in bacteria and nearly 6,000 in humans.

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"The protoribosome came about when a bunch of RNA nucleotide chains self-assembled into two semisymmetrical walls hooked up to create a pocket. Endless other structures must have accidentally self-assembled around the same time, but the protoribosome survived, "going viral," it seems, because it performed useful functions and, thanks to RNA's intrinsic capabilities, it could self-replicate.

"When two activated amino acids happened to interact with one another within this pocket, they formed a bond, facilitated by the prevailing chemical conditions. Those amino acids may have arisen on Earth or, as some argue, landed with asteroids from outer space, but their origin is irrelevant to our story. What matters is that within the protoribosome, two activated amino acids could bind to each other. Later on, such bond making united many more amino acids, linking them into a chain.

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"To the team's delight, the synthetic protoribosomes created in the lab rose to the task. "Peptide bond formation is the most vital activity in any cell, and we've shown that it can take place within a protoribosome," Bose says.

"'The proposed protoribosome might be the missing link between an RNA-dominated world—one that may have existed before proteins and DNA appeared—and life that is based on proteins and nucleic acids, as we know it today," Bashan says."

Comment: all protein function is based on the proper series/sequence of amino acids and its special folded shape. Also, they are describing molecules with thousands of amino acids that must be in a correct position to function. This is the usual fairy tale of chance development shown by intelligent design in the lab.