Formamide as the main building block in the origin of nucleic acids

Costanzo Giovanna, Saladino Raffaele, Crestini Claudia, Ciciriello Fabiana, Di

Description

The simplest molecules grouping the four most common elements of the universe H,C,O and N (with the exception of the biologically inert He) are isocyanate HNCO and formamide H 2 NCOH. Reasons for the availability of formamide on prebiotic Earth are presented. We review evidence showing that formamide in the presence of largely available catalysts and by moderate heating yields the complete set of nucleic bases necessary for the formation of nucleic acids. Formamide also favours the formation of acyclonucleosides and the phosphorylation and trans-phosphorylation of nucleosides, thus providing a plausible chemical frame for the passage from a simple one-carbon compound to nucleic polymers. Physico-chemical conditions exist in which formamide favours the stability of the phosphoester bonds in nucleic polymers relative to that of the same bonds in monomers. Starting from a formamide-laden environment subject only to the laws of chemistry, a hypothesis is outlined sketching the passage towards an aqueous world in which Darwinian rules apply.

Informations

• Publié par: biomed
• Publié le: 01 janvier 2007
• Nombre de lectures: 8
• Langue: English

Extrait

BMC Evolutionary Biology

BioMedCentral

Open Access Research Formamide as the main building block in the origin of nucleic acids 1 1,23 Giovanna Costanzo, Raffaele Saladino, Claudia Crestini, 4 5 Fabiana Cicirielloand Ernesto Di Mauro*

1 2 Address: Istitutodi Biologia e Patologia Molecolari, CNR, P.le Aldo Moro, 5, Rome 00185, Italy,Dipartimento A.B.A.C., Università della Tuscia, 3 Via San Camillo De Lellis, Viterbo, Italy,Marine Dipartimento di Scienze e Tecnologie Chimiche, Università "Tor Vergata", Rome 00133, Italy, 4 Fondazione "Istituto PasteurFondazione CenciBolognetti" c/o Dipartimento di Genetica e Biologia Molecolare, Università "La Sapienza" di 5 Roma, P.le Aldo Moro, 5, Rome 00185, Italy andErnesto Di Mauro, Dipartimento di Genetica e Biologia Molecolare, Università "La Sapienza" di Roma, P.le Aldo Moro, 5, 00185 Rome, Italy Email: Giovanna Costanzo  [e-mail]; Raffaele Saladino  [e-mail]; Claudia Crestini  [e-mail]; Fabiana Ciciriello  [e-mail]; Ernesto Di Mauro*  [e-mail] * Corresponding author

fromSecond Congress of Italian Evolutionary Biologists (First Congress of the Italian Society for Evolutionary Biology) Florence, Italy. 4–7 September 2006

Published: 16 August 2007 BMC Evolutionary Biology2007,7(Suppl 2):S1

doi:10.1186/1471-2148-7-S2-S1

<supplement><title><p>SecondCongressofItailanEvolutionaryBiologists(FirstCongressoftheItalianSocietyforEvolutionaryBiology)</p></title><editor>RenatoFani,DavidCaramelil,PietroLiò</editor><sponsor><note>Thesupplementorganiserswouldilketoacknowledgethefollowingorganisationsfortheirfinancialsupportofthemeeting:EnteCassadiRisparmiodiFirenze,Sarstedt,CelBio,UniversitàdegilStudidiFirenze.</note></sponsor><note>Research</note><url>http://www.biomedcentral.com/content/pd/f1471-2148-7-S2-info.pdf</url></supplement> This article is available from: http://www.biomedcentral.com/1471-2148/7/S2/S1 © 2007 Costanzo et al; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract The simplest molecules grouping the four most common elements of the universe H,C,O and N (with the exception of the biologically inert He) are isocyanate HNCO and formamide H NCOH. 2 Reasons for the availability of formamide on prebiotic Earth are presented. We review evidence showing that formamide in the presence of largely available catalysts and by moderate heating yields the complete set of nucleic bases necessary for the formation of nucleic acids. Formamide also favours the formation of acyclonucleosides and the phosphorylation and trans-phosphorylation of nucleosides, thus providing a plausible chemical frame for the passage from a simple one-carbon compound to nucleic polymers. Physico-chemical conditions exist in which formamide favours the stability of the phosphoester bonds in nucleic polymers relative to that of the same bonds in monomers. Starting from a formamide-laden environment subject only to the laws of chemistry, a hypothesis is outlined sketching the passage towards an aqueous world in which Darwinian rules apply.

Background Life is a sturdy phenomenon and its initial stepsbona fide originated from robust chemical frames based on firm thermodynamic ground. These assumptions on the sim plicity and the necessity of the prebiogenic processes are mitigated by the consideration that the genetic mecha nisms onto which relies lifeasweknowit today are com binatorially elaborated. In passing from the initial self

organization of chemical information to the potentially infinite complexity of interplaying genotypes and pheno types that we experience today, evolution did necessarily play the key role.

We have focused on two aspects of the problem: the defi nition of a plausible chemical frame into which the first spontaneous syntheses could have taken place; the evolu

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