Ancient enzymes adapted to a cooler Earth to keep life’s chemical reactions going
Re-creating 3-billion-year genetic history of adenylate kinase reveals evolutionary path
HOT AND COLD Scientists reconstructed three billion years of genetic history for the adenylate kinase enzyme (shown here bound to another molecule) to see how ancient enzymes might have adapted to a cooler Earth.
Ayacop/Wikimedia Commons
Like lifelong Floridians dropped into a Wisconsin winter, enzymes accustomed to warmth don’t always fare well in colder climes. But ancient heat-loving enzymes forced to adapt to a cooling Earth managed to swap out parts to keep chemical reactions going, scientists report online December 22 in Science.
By reconstructing enzymes as they might have looked billions of years ago, the research “helps to explain the natural evolutionary history of life on this planet,” says Yousif Shamoo, a biochemist at Rice University in Houston who wasn’t part of the study. And the findings question the idea that enzymes must sacrifice their stability to become more active.
Enzymes are natural catalysts that jump-start essential chemical reactions inside living things. Most work only within a specific temperature range. Too cold, and they can’t get
