Xeno nucleic acid

Xenonucleic acids (XNAs) are synthetic nucleic acid analogues that are engineered with structurally distinct components, such as alternative nucleosides, sugars, or backbones.

XNAs have fundamentally different properties from endogenous nucleic acids, enabling different specialized applications, such as therapeutics, probes, or functional molecules. For instance, peptide nucleic acids, the backbones of which are made up of repeating aminoethylglycine units, are extremely stable and resistant to degradation by nucleases because they are not recognised.

The same nucleobases can be used to store genetic information and interact with DNA, RNA, or other XNA bases, but the different backbone gives the compound different properties. Their altered chemical structure means they cannot be processed by naturally occurring cellular processes. For instance, natural DNA polymerases cannot read and duplicate the alien information, thus the genetic information stored in XNA is invisible to DNA-based organisms.

As of 2011, at least six types of synthetic sugars have been shown to form nucleic acid backbones that can store and retrieve genetic information. Research is now being focused to create synthetic polymerases to transform XNAs. The study of the production and application of XNA molecules has created the field of current xenobiology.