Threose nucleic acid
Threose nucleic acid (TNA) is an artificial genetic polymer in which the natural five-carbon ribose sugar found in RNA has been replaced by an unnatural four-carbon threose sugar. Invented by Albert Eschenmoser as part of his quest to explore the chemical etiology of RNA, TNA has become an important synthetic genetic polymer as a xeno nucleic acid (XNA) due to its ability to efficiently base pair with complementary sequences of DNA and RNA. The main difference between TNA and DNA/RNA is their backbones.