Threose nucleic acid

Threose nucleic acid (TNA) is a polymer similar to DNA or RNA but differing in the composition of its "backbone". TNA is not known to occur naturally; they are synthesized chemically.

DNA and RNA have a deoxyribose and ribose sugar backbone, respectively, whereas TNA's backbone is composed of repeating threose units linked by phosphodiester bonds. The threose molecule is easier to assemble than ribose making it a possible precursor to RNA.

DNA-TNA hybrid chains have been made in the laboratory using DNA polymerase.

TNA can hybridize with RNA and DNA in a sequence-specific manner; this capability and chemical simplicity suggests that TNA could have preceded RNA as genetic material.

See also

• Oligonucleotide synthesis
• Abiogenesis
• Glycol nucleic acid
• Peptide nucleic acid

External links

• Was simple TNA the first nucleic acid on Earth to carry a genetic code?, New Scientist
• ORIGIN OF LIFE: A Simpler Nucleic Acid, Leslie Orgel

References

• Orgel, Leslie (November 2000). "A Simpler Nucleic Acid". Science 290 (5495): 1306–1307. doi:10.1126/science.290.5495.1306. PMID 11185405. 

• Watt, Gregory (February 2005). "Modified nucleic acids on display". Nature Chemical Biology. doi:10.1038/nchembio005. http://www.nature.com/nchembio/journal/vaop/nprelaunch/full/nchembio005.html. 

• Schoning, K; Scholz P; Guntha S; Wu X; Krishnamurthy R; Eschenmoser A (November 2000). "Chemical etiology of nucleic acid structure: the alpha-threofuranosyl-(3'->2') oligonucleotide system.". Science 290 (5495): 1347–51. doi:10.1126/science.290.5495.1347. PMID 11082060.