(Phys.org) —One of the biggest questions in science is how life arose from the chemical soup that existed on early Earth. One theory is that RNA, a close relative of DNA, was the first genetic molecule to arise around 4 billion years ago, but in a primitive form that later evolved into the RNA and DNA molecules that we have in life today. New research shows one way this chain of events might have started.
Today,
genetic information is stored in DNA. RNA is created from DNA to put that information into action. RNA can direct the creation of proteins and perform other essential functions of
life that DNA can't do. RNA's versatility is one reason that scientists think this polymer came first, with DNA evolving later as a better way to store genetic information for the long haul. But like DNA, RNA also could be a product of evolution, scientists theorize.
Chemists at the Georgia Institute of Technology have shown how molecules that may have been present on early Earth can self-assemble into structures that could represent a starting point of RNA. The spontaneous formation of RNA
building blocksis seen as a crucial step in the origin of life, but one that scientists have struggled with for decades.
"In our study, we demonstrate a reaction that we see as important for the formation of the earliest RNA-like molecules," said Nicholas Hud, professor of Chemistry and Biochemistry at Georgia Tech, where he's also the director of the Center for Chemical Evolution.
The study was published Dec. 14 online in the
Journal of the American Chemical Society. The research was funded by the National Science Foundation and NASA.
The researchers demonstrated this property of the TAP nucleosides by adding another molecule to their reaction mixture, called cyanuric acid, which is known to interact with TAP. Even in the unpurified reaction mixture, noncovalent polymers formed with thousands of paired nucleosides.
"It is amazing that these nucleosides and bases actually assemble on their own, as life today requires complex enzymes to bring together RNA building blocks and to spatially order them prior to polymerization,"said Brian Cafferty, a graduate student at Georgia Tech and co-author of the study
The study demonstrated one possible way that the building blocks for an ancestor of RNA could have come together on early Earth. TAP is an intriguing candidate for one of the first bases that eventually led to modern RNA molecules, but there are certainly others, Hud said.
Future work, in Hud's lab and by other laboratories in the Center for Chemical Evolution, will investigate the origins of RNA's phosphate backbone, as well as other pathways toward modern RNA.
"We're looking for a simple, robust chemistry that can explain the earliest origin of RNA or its ancestor," Hud said.
Read more at:
New Study Brings Scientists Closer to the Origin of RNA
just read a passage or two out of a book with the earliest part written a generation after their Sky Pixie had passed. Who is lazy?
