On the origin of life: Studying how the first biomolecule self-replicated
It's the ultimate chicken-or-egg conundrum: What was the "mother" molecule that led to the formation of life? And how did it replicate itself? One prominent school of thought proposes that RNA is the answer to the first question. Now, in ACS Central Science, researchers in this camp demonstrate RNA has more flexibility in how it recognizes itself than previously believed. The finding might change how we picture the first chemical steps towards replication and life.
|When a short piece of RNA (green) binds a nucleotide analogue (PZG, pink), three different binding modes|
are observed, suggesting canonical Watson-Crick is not the only possible mode of RNA self-recognition
[Credit: American Chemical Society]
They monitored how an analogue of a free nucleotide interacted with a short piece of RNA using the classic method of X-ray crystallography -- the same technique used more than fifty years ago in the original discovery of DNA's 3-D structure. In addition to forming the expected canonical Watson-Crick pairs, the RNA bonded with the analogue in other less frequently observed ways. Under prebiotic conditions, these unexpected non-Watson-Crick pairings might have caused dead-ends to replication. Thus, the results suggest that the first steps toward life required more trial and error than previously thought.
Source: American Chemical Society [November 03, 2016]