Generation of long RNA chains in water

Abstract

The synthesis of RNA chains from 3′,5′-cAMP and 3′,5′-cGMP was observed. The RNA chains formed in water, at moderate temperatures (40-90 °C), in the absence of enzymes or inorganic catalysts. As determined by RNase analyses, the bonds formed were canonical 3′,5′-phosphodiester bonds. The polymerizations are based on two reactions not previously described: 1) oligomerization of 3′, 5′-cGMP to 25-nucleotide-long RNA molecules, and of 3′,5′-cAMP to 4 to 8-nucleotide-long molecules. Oligonucleotide A molecules were further extended by reciprocal terminal ligation to yield RNA molecules up to > 120 nucleotides long and 2) chain extension by terminal ligation of newly polymerized products of 3′,5′-cGMP on preformed oligonucleotides. The enzyme- and template-independent synthesis of long oligomers in water from prebiotically affordable precursors approaches the concept of spontaneous generation of (pre)genetic information. © 2009 by The American Society for Biochemistry and Molecular Biology, Inc.