Enzymes facilitate many processes necessary for life. Using xeno nucleic acid, researchers have been able to manufacture synthetic enzymes, reinforcing the possibility that life can evolve without RNA or DNA, two molecules indispensable to life.
Researchers from the Medical Research Council's Laboratory of Molecular Biology turned to synthetic biology to create the first known enzymes out of unnatural building blocks. XNAs are chemical cousins to DNA but they don't occur in nature. Instead, they form the building blocks of synthetic genetic systems that other researchers have previously established.
Led by Alexander Taylor, the researchers called the enzymes they developed from XNA "XNAzymes." These catalyze a handful of "cut and paste" reactions that highlight the possibility that enzymes can evolve from non-biological chemistries.
With the creation of XNAzymes, the first empirical evidence that catalysis, one of life's hallmarks, can be produced using building blocks that don't occur in nature has been achieved. According to researchers, the results of their work imply that DNA, RNA and other proteins are not necessarily special because the possibility now exists that other different chemicals can be used to create life.
"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," said Nobel Prize winner Jack Szostak about the researchers' work.
What are the other possibilities that XNAs hold? According to Philipp Holliger, co-author of the study, the genetic material may be of particular use in medicine. Given XNAs are not naturally occurring, they can't be broken down by the body. However, they can still cut and eradicate RNA, allowing them to work as drugs against RNA viruses. XNAs may also disrupt RNA messages that trigger the development of cancer.
Aside from Taylor and Holliger, other authors for the study include Vitor Pinheiro, Piet Herdewijn, Matthew Smola, Kevin Weeks, Alexey Morgunov, Christopher Cozens and Sew Peak-Chew. Their work was financially supported by the MRC, European Science Foundation, U.S. National Science Foundation, European Research Council, European Union Framework, and Biotechnology and Biological Sciences Research Council.
The Laboratory of Molecular Biology that paved the way for the creation of XNAzymes is the same laboratory where the DNA structure was discovered by James Watson and Francis Crick in 1953.
