DNA and his cousin RNA stores genetic information and provides life as we know it – but what if millions of lesser-known chemicals could do the same?
A new study suggests that more than 1 million chemicals can encode biological information the same way DNA does. The new study, published on September 9 at Journal of Chemical Information and Modeling, may point the way to new goals for pharmaceuticals, explained as a first life evolved on Earth, and even help us look for life forms outside our planet, the authors wrote.
"It's really exciting to consider the potential for an alternative genetically systems … that these may have appeared and evolved in different environments, maybe even on other planets or moons within our solar system, "said co-author Jaye Goodwin, a chemist at Emory University, it said in a statement.
Both DNA and RNA, the two known types of nucleic acids, contain chemical bits called nucleotides that bind in a certain order and transmit different data, depending on their sequence, similar to individual letters in a written sentence. Several natural and artificial molecules imitate the basic structure of DNA, but so far no one has attempted to count how many of these looks may exist, the authors wrote.
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"There are two types of nucleic acids in biology," said co-author Jimmy Clive, a chemist at the Tokyo Institute of Technology. "We wanted to know if there was another one to be found, and even a million more."
"The answer is, it looks like there's a lot, much more than expected," Clive said.
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The authors designed a computer program to generate chemical formulas for nucleic acid-like molecules. In DNA, nucleotides merge into different pairs and fold together so that scientists have ensured that their generated molecules can form in the same way. Eventually, their program collected more than 1,160,000 different molecules that met these basic criteria.
"We were surprised by the outcome of this calculation," said co-author Marcus Meringer, a chemist at the German Aerospace Center in Cologne. "It would be very difficult to estimate a priori that there are more than a million nucleic acids as scaffolds. Now we know and we can begin to test some of these in the lab."
A multitude of views can clarify the story of how life on Earth happened before DNA and RNA dominated the world of biology. Theoretically, evolution "Test paths" may have been performed with some of these other molecules before settling on nucleic acids as the best carriers of genetic data, the authors suggest.
Appearance can fuel the future medical progress, they added. Nucleotide-like drugs are already being used to undermine dangerous viruses and malignant cancer cells in the human body, the statement said. With the help of a library of structurally similar molecules, drug developers can potentially adopt DNA-like weapons as a major weapon in the fight against disease.
"It is absolutely fascinating to think that using modern computer techniques we can stumble upon new drugs when we look for alternative molecules to DNA and RNA that can store inherited information," said co-author Peter Burger, a biochemist at Emory University.
Originally posted on Live Science.