Book of Abstracts: Albany 2011
June 14-18 2011
©Adenine Press (2010)
Spontaneous Generation of RNA in Water
Definition of life is an open problem. The largely accepted wording: “Life is a self sustained chemical system capable of undergoing Darwinian evolution” (1) attains a solid operative sense but it is more the description of a process than a formal definition of a system. If we have difficulty in even formulating a rigorous definition of life, certainly we do not know how it started. In recent years, progress has been made in the search for the unitary chemical frame into which the first reactions lighted up and started accumulating and evolving chemical information. In collaboration with R. Saladino group (Università della Tuscia, Italy), we have shown that formamide (HCONH2), one of the simplest molecules grouping the four most common elements of the universe H, C, O and N, provides a chemical frame potentially affording all the monomeric components necessary for the formation of nucleic polymers (lastly reviewed in Saladino 2). In the presence of the appropriate catalysts and by moderate heating, formamide yields a complete set of nucleic bases, acyclonucleosides and favours both their phosphorylation and transphosphorylation.
Nucleotide phosphorylation and RNA oligomerization take place in water in non-enzymatic abiotic conditions. At moderate temperatures (40-90°C) RNA chains up to 120 nucleotides long may form from 3’, 5’-cAMP and 3’, 5’-cGMP, in the absence of enzymes or inorganic catalysts (3). Mechanisms of abiotic RNA chain extension and ligation based on base-pairing and base-stacking interactions were also observed (4, 5). The enzyme and the template-independent synthesis of long oligomers in water, from prebiotically affordable precursors, approaches the concept of spontaneous generation and evolution of (pre)genetic information.
1 Istituto di Biologia e Patologia Molecolari