Nuove possibilità di produzione di oligonluceotidi di sintesi contenenti LNA, Locked Nucleic Acids, in cui esiste una struttura chiusa, locked, con un legame ciclico tra il Carbonio in 2' e l'ossidrile sul carbonio in 4' nel ribosio dei nucleotidi di una molecola di DNA che dà una conformazione come se fosse di RNA. Nel DNA, l'acido deossiribonucleico è privo dell' idrossile OH in 2' sul ribosio, mentre negli LNA questo carbonio partecipa al legame con l'OH sul carbonio in 4'.
Sequenze conententi LNA sono molto utilizzate in biologia molecolare, in terapia clinica e per silenziare mRNA e microRNA.
Non ci sarà più bisogno di ordinarli dalla Exiqon o chi per loro abbia un licence agreement.
L'aticolo che descrive nuove DNA polimerasi con la capacità di sintentizzare queste sequenze e altre ancora (con nucleotidi con proprietà ancora da scorpire) è apparso oggi su Science
- Unnatural Bases
- The genetic basis of all life on the planet is comprised of deoxyribonucleic acid (DNA) with four nitrogenous nucleotide bases, abbreviated to A, G, C, and T. But there are variations on this theme, and Pinheiro et al. (p. 341; see the Perspective by Joyce) describe the directed evolution of unnatural nucleic acid-like genetic polymers. Variant enzymes were developed that efficiently transcribed DNA to anhydrohexitol (HNA), cyclohexenyl (CeNA), locked (LNA), and threofuranosyl (TNA) nuceic acid analogs. Further variant enzymes were developed to reverse-transcribe these analogs back to DNA. Thus, man-made nucleic acid analogs can be designed and selected that have the potential to operate in a way analogous to the natural process of heredity and evolution.
- Genetics provides a mechanism for molecular memory and thus the basis for Darwinian evolution. It involves the storage and propagation of molecular information and the refinement of that information through experience and differential survival. Heretofore, the only molecules known to be capable of undergoing Darwinian evolution were RNA and DNA, the genetic molecules of biology. But on page 341 of this issue, Pinheiro et al. (1) expand the palette considerably. They report six alternative genetic polymers that can be used to store and propagate information; one of these was made to undergo Darwinian evolution in response to imposed selection constraints. The work heralds the era of synthetic genetics, with implications for exobiology, biotechnology, and understanding of life itself.
Synthetic Genetic Polymers Capable of Heredity and Evolution
Vitor B. Pinheiro, Alexander I. Taylor, Christopher Cozens, Mikhail Abramov, Marleen Renders, Su Zhang, John C. Chaput, Jesper Wengel, Sew-Yeu Peak-Chew, Stephen H. McLaughlin, Piet Herdewijn, and Philipp Holliger
