There can be millions of different structures with the ability to store genetic information, according to a recent book
DNA stores genetic information that describes all life on Earth, beneath the shape of a twisted scaffold lined with a sequence composed of four molecules encoding data. But is DNA the best way to store biological data for any purpose? What if there are better molecules for other purposes?
New research indicates "the existence of large spaces of unexplored chemistry related to pharmacology and biochemistry and efforts to understand the origin of life," according to a paper published in the Journal of Chemical Information and Modeling.
Researchers have discovered a wide variety of possible storage molecules using a program called MOLGEN 5.0. They began by determining what a nucleic acid-like component should be made of, starting with a 'fuzzy' basic molecular formula. They also defined what its structure should be: It needs a piece that another molecule that reads the component can recognize as data (in DNA it is A, T, C and G or nucleobase), as well as binding points of a recognizable unit to the scaffold and to bind each of these components into a larger molecule. Then they used another program called Pipeline Pilot to generate new structures with the same chemical formulas to see what they might have missed. Finally, they compared the output to molecule databases to check that any of their new molecules already exist, and used another computer program to exclude molecules that violate various chemistry constraints.
No one actually produces these molecules. According to the paper, this work is the "first systematic attempt" to enumerate, count and describe the space of all nucleic acid-like molecules.
This team of scientists first simply examines molecules with the same chemical formula as, but different structure from, RNA – single stranded copies of DNA that the body actually uses as instructions for building proteins. Extending this study to more general chemical formulas generates a vast list of unexplored possibilities for what genetic material may look like: 1160 990 different structures.
"It is truly exciting to consider the potential for alternative genetic systems based on these analogous nucleosides – that they are likely to occur and evolve in different environments, perhaps even on other planets or moons in our solar system," says the author of the study Jay Goodwin, a senior research fellow in chemistry at Emory University, said in a message. "These alternating genetic systems can extend our conception of the" central dogma "of biology in new evolutionary directions, in response [to]and healthy for ever more challenging environments here on Earth."
Given these other possible Genetic molecules could help scientists better understand the origin of RNA and DNA and why they look the way they do on Earth. It can also help synthetic biologists who hope to use DNA-like molecules as biological storage disks.
That's exciting. "This document is a remarkably in-depth analysis" of the field, George Church, a professor of genetics at Harvard Medical School, told Gizmodo in an email. Now that there is such an analysis, "we may be surprised at how quickly the community is doing this and testing them for possible usefulness."
In other words, now that the list is there, expect scientists to start digging and research whether each used these possible molecules in the real world.