Could someone tell me if DNA repair enzymes could theoretically repair DNA damage of any age, or if they can only repair recent DNA damage (ie from one or two generations ago) and why? Also would it possible to genetically alter someone (an adult) to overexpress DNA repair enzymes? thanks for the education
I always thought that the activity of these enzymes depended on the chemistry of the lesion, not so much the age of the lesion. I don’t know this for a fact, but I would guess that if the damage was not repaired after the first or second generation before being encountered by a repair enzyme, the enzyme would still do its thing and repair the lesion. I think repair enzymes do usually act on freshly damaged DNA and their efficiency (or lack of it) has an affect on the ability of the cells to survive the damage. A cell which doesn’t repair a significant amount of DNA damage right away is less likely to be around for a second or third try at repair, it seems to me. Lack of repair enzymes can be involved in certain diseases–Xeroderma pigmentosa comes to mind; there may be others. I’m not aware of anyone trying to genetically enhance themselves by overexpressing their DNA repair enzymes. Maybe they’d be challenging Zonker for his world champioship tanning title.