Genome complexity: how enzyme changes RNA to DNA (Introduction)

by David Turell , Tuesday, March 31, 2020, 22:12 (1485 days ago) @ David Turell

A high speed method captures how a complex enzyme does its work, and it is ot as previously thought:

https://phys.org/news/2020-03-biochemists-visualize-enzyme.html

"The enzyme, ribonucleotide reductase (RNR), is responsible for converting RNA building blocks into DNA building blocks, in order to build new DNA strands and repair old ones... But for decades, scientists struggled to determine how the enzyme is activated because it happens so quickly. Now, for the first time, researchers have trapped the enzyme in its active state and observed how the enzyme changes shape, bringing its two subunits closer together and transferring the energy needed to produce the building blocks for DNA assembly.

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"It wasn't until the Drennan lab gained access to a key technological advancement—cryo-electron microscopy—that they could snap high-resolution images of these "trapped" enzymes from the Stubbe lab and get a closer look.

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"The combination of these techniques allowed the team to visualize the complex molecular dance that allows the enzyme to transport the catalytic "firepower" from one subunit to the next, in order to generate DNA building blocks. This firepower is derived from a highly reactive unpaired electron (a radical), which must be carefully controlled to prevent damage to the enzyme. (my bold)

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"'Before this study, we knew this molecular dance was happening, but we'd never seen the dance in action," he says. "But now that we have a structure for RNR in its active state, we have a much better idea about how the different components of the enzyme are moving and interacting in order to transfer the radical across long distances."

"Although this molecular dance brings the subunits together, there is still considerable distance between them: The radical must travel 35-40 angstroms from the first subunit to the second. This journey is roughly 10 times farther than the average radical transfer, according to Drennan. The radical must then travel back to its starting place and be stored safely, all within a fraction of a second before the enzyme returns to its normal conformation."

Comment: my bold is the key point: fine-tuned control of a dangerous radical (electron on the loose but really not). Not by chance from hunt and peck. There must be a designer. If Darwin had known these facts, his book would not be written in the same way. Darwinism must be preserved to support atheism.