Biological complexity: Backup corrections for broken DNA (Introduction)

by David Turell , Monday, July 06, 2020, 23:05 (1382 days ago) @ David Turell

Yes, dhw, errors do occur in DNA replication, but God inserted backup repair mechanisms:

https://phys.org/news/2020-07-great-specificity-action-enzymes-double-strand.html

"Dr. Daley is first author of research, published June 18 in the journal Nature Communications, that sheds light on a double-strand break repair process called homologous recombination. Joined by senior authors Patrick Sung, DPhil, and Sandeep Burma, Ph.D., and other collaborators, Dr. Daley found that among an array of mechanisms that initiate homologous recombination, each one is quite different. Homologous recombination is initiated by a process called DNA end resection where one of the two strands of DNA at a break is chewed back

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"'For a decade we have known that resection enzymes are at the forefront of homologous recombination. What we didn't know is why so many of these enzymes are involved, and why we need three or four different enzymes that seem to accomplish the same task in repairing double-strand breaks."

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"'It's like an engine mechanic who has a set of tools at his disposal," Dr. Sung said. "The tool he uses depends on the issue that needs to be repaired. In like fashion, each DNA repair tool in our cells is designed to repair a distinctive type of break in our DNA."

"The research team studied complex breaks that featured double-strand breaks with other kinds of DNA damage nearby—such complex breaks are more relevant physiologically, Dr. Daley said. Studies in the field of DNA repair usually tend to look at simpler versions of double-strand breaks, he said. Dr. Daley found that each resection enzyme is tailored to deal with a specific type of complex break, which explains why a diverse toolkit of resection enzymes has evolved over millennia." (my bold)

Comment: No surprise. Enough repair tools to cover all types of DNA tears. It seems God recognized errors would occur and provided all the necessary tools for perfect reproduction. Makes logical sense recognizing no biological living system can operate at high speed perfectly. This discussion about errors has begun years after the start of this website. I have't hidden it. Courses in biochemistry describe it as an obvious problem, and point out all the corrective mechanisms required. We would not have evolved without them.