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.

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 specifically base pair with RNA and DNA; this capability and chemical simplicity suggests that TNA could have preceded RNA as genetic material.

[edit] See also

• Abiogenesis
• Glycol nucleic acid
• Peptide nucleic acid

[edit] 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

[edit] References

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

• 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: 1347. doi:10.1126/science.290.5495.1347. PMID 11082060. 

v • d • e Types of nucleic acids Constituents Nucleobases · Nucleosides · Nucleotides · Deoxynucleotides Ribonucleic acids (coding and non-coding) translation: mRNA (pre-mRNA/hnRNA) · tRNA · rRNA · tmRNA regulatory: miRNA · siRNA · piRNA · aRNA RNA processing: snRNA · snoRNA other/ungrouped: gRNA · shRNA · stRNA · ta-siRNA Deoxyribonucleic acids cDNA · cpDNA · gDNA · msDNA · mtDNA Nucleic acid analogues GNA · LNA · PNA · TNA · morpholino Cloning vectors phagemid · plasmid · lambda phage · cosmid · fosmid · PAC · BAC · YAC · HAC Major families of biochemicals Saccharides/Carbohydrates/Glycosides · Amino acids/Peptides/Proteins/Glycoproteins · Lipids/Terpenes/Steroids/Carotenoids · Alkaloids/Nucleobases/Nucleic acids · Cofactors/Phenylpropanoids/Polyketides/Tetrapyrroles

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