Origem da vida: gerando moléculas de RNA na água

Origin of Life: Generating RNA Molecules in Water

ScienceDaily (Nov. 25, 2009) — A key question in the origin of biological molecules like RNA and DNA is how they first came together billions of years ago from simple precursors. Researchers in Italy have reconstructed one of the earliest evolutionary steps yet: generating long chains of RNA from individual subunits using nothing but warm water.

Many researchers believe that RNA was one of the first biological molecules present, before DNA and proteins; however, there has been little success in recreating the formation on RNA from simple "prebiotic" molecules that likely were present on primordial earth billions of years ago.
Now, Ernesto Di Mauro and colleagues found that ancient molecules called cyclic nucleotides can merge together in water and form polymers over 100 nucleotides long in water ranging from 40-90 °C -- similar to water temperatures on ancient Earth.
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Journal Reference:
Giovanna Costanzo, Samanta Pino, Fabiana Ciciriello and Ernesto Di Mauro. Generation of long RNA chains in water. Journal of Biological Chemistry, 2009; DOI: 10.1074/jbc.M109.041905

Generation of Long RNA Chains in Water*

Giovanna Costanzo‡,1, Samanta Pino§,1, Fabiana Ciciriello§ and Ernesto Di Mauro¶,2

- Author Affiliations

From the ‡Istituto di Biologia e Patologia Molecolari, CNR,
the §Dipartimento di Genetica e Biologia Molecolare, Università La Sapienza di Roma, and

the ¶Fondazione Istituto Pasteur-Fondazione Cenci-Bolognetti, c/o Dipartimento di Genetica e Biologia Molecolare, Università La Sapienza di Roma, P. le Aldo Moro, 5, Rome 00185, Italy

2 To whom correspondence should be addressed. Tel.: 39-06-4991-2880; Fax: 39-06-4991-2500; E-mail: Ernesto.dimauro@uniroma1.it.

↵1 Both authors contributed equally to this work.

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.

Footnotes

↵* This work was supported by the Italian Space Agency, the MoMa project, and Agenzia Spaziale Italiana-Istituto Nazionale di Astrofisica (Grant I/015/07/0, Esplorazione del Sistema Solare) Italy.

↵3 The abbreviation used is:
XMP any one of AMP, GMP, CMP, or UMP.

Received July 7, 2009.

Revision received October 2, 2009.

© 2009 by The American Society for Biochemistry and Molecular Biology, Inc.

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