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      The RNA World: molecular cooperation at the origins of life.

      1 , 2
      Nature reviews. Genetics

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          Abstract

          The RNA World concept posits that there was a period of time in primitive Earth's history - about 4 billion years ago - when the primary living substance was RNA or something chemically similar. In the past 50 years, this idea has gone from speculation to a prevailing idea. In this Review, we summarize the key logic behind the RNA World and describe some of the most important recent advances that have been made to support and expand this logic. We also discuss the ways in which molecular cooperation involving RNAs would facilitate the emergence and early evolution of life. The immediate future of RNA World research should be a very dynamic one.

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          Most cited references94

          • Record: found
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          Systematic evolution of ligands by exponential enrichment: RNA ligands to bacteriophage T4 DNA polymerase.

          L Gold, C Tuerk (1990)
          High-affinity nucleic acid ligands for a protein were isolated by a procedure that depends on alternate cycles of ligand selection from pools of variant sequences and amplification of the bound species. Multiple rounds exponentially enrich the population for the highest affinity species that can be clonally isolated and characterized. In particular one eight-base region of an RNA that interacts with the T4 DNA polymerase was chosen and randomized. Two different sequences were selected by this procedure from the calculated pool of 65,536 species. One is the wild-type sequence found in the bacteriophage mRNA; one is varied from wild type at four positions. The binding constants of these two RNA's to T4 DNA polymerase are equivalent. These protocols with minimal modification can yield high-affinity ligands for any protein that binds nucleic acids as part of its function; high-affinity ligands could conceivably be developed for any target molecule.
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            The origin of the genetic code.

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              Synthesis of activated pyrimidine ribonucleotides in prebiotically plausible conditions.

              At some stage in the origin of life, an informational polymer must have arisen by purely chemical means. According to one version of the 'RNA world' hypothesis this polymer was RNA, but attempts to provide experimental support for this have failed. In particular, although there has been some success demonstrating that 'activated' ribonucleotides can polymerize to form RNA, it is far from obvious how such ribonucleotides could have formed from their constituent parts (ribose and nucleobases). Ribose is difficult to form selectively, and the addition of nucleobases to ribose is inefficient in the case of purines and does not occur at all in the case of the canonical pyrimidines. Here we show that activated pyrimidine ribonucleotides can be formed in a short sequence that bypasses free ribose and the nucleobases, and instead proceeds through arabinose amino-oxazoline and anhydronucleoside intermediates. The starting materials for the synthesis-cyanamide, cyanoacetylene, glycolaldehyde, glyceraldehyde and inorganic phosphate-are plausible prebiotic feedstock molecules, and the conditions of the synthesis are consistent with potential early-Earth geochemical models. Although inorganic phosphate is only incorporated into the nucleotides at a late stage of the sequence, its presence from the start is essential as it controls three reactions in the earlier stages by acting as a general acid/base catalyst, a nucleophilic catalyst, a pH buffer and a chemical buffer. For prebiotic reaction sequences, our results highlight the importance of working with mixed chemical systems in which reactants for a particular reaction step can also control other steps.
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                Author and article information

                Journal
                Nat. Rev. Genet.
                Nature reviews. Genetics
                1471-0064
                1471-0056
                Jan 2015
                : 16
                : 1
                Affiliations
                [1 ] Origins Institute and Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada.
                [2 ] Department of Chemistry, Portland State University, PO Box 751, Portland, Oregon 97207, USA.
                Article
                nrg3841
                10.1038/nrg3841
                25385129
                dc3bf572-9d3c-4a75-aee4-e449939bb731
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