Xeno-nucleic acids, or XNAs, can act as catalysts, report researchers led by MRC Laboratory of Molecular Biology's Philipp Holliger in Nature this week. They've dubbed these synthetic catalysts XNAzymes.
He and his colleagues reported in Science in 2012 on their development of six XNAs not found in nature that could store genetic information.
They've now shown in Nature that four XNAs — ANA, FANA, HNA, and CeNA — house RNA endonucleases and that one — FANA — can work as an RNA endonuclease, RNA ligase, and XNA ligase. On Earth, one of the first steps in the development of life is thought to have been the evolution of RNA into a self-copying enzyme, New Scientist notes.
"Our work with XNA shows that there's no fundamental imperative for RNA and DNA to be prerequisites for life," Holliger tells the New Scientist.
Indeed, he argues that on other planets that XNAs could dominate as genetic material rather than DNA and RNA, though XNAs haven't yet been shown to be able to copy themselves.
"The possibility that life elsewhere, on exoplanets, could have started with something other than RNA or DNA is quite interesting, but the primordial biopolymer for any form of life must satisfy other constraints as well, such as being something that can be generated by prebiotic chemistry and replicated efficiently," Harvard University's Jack Szostak tells the New Scientist. "Whether XNA can satisfy these constraints, as well as providing useful functions, remains an open question."