Surgimento de um código na polimerização de aminoácidos ao longo de 'templates' de RNA

domingo, fevereiro 28, 2010

Emergence of a Code in the Polymerization of Amino Acids along RNA Templates

Jean Lehmann1*, Michel Cibils2, Albert Libchaber1

1 Center for Studies in Physics and Biology, The Rockefeller University, New York, New York, United States of America, 2 Section de Mathématiques, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland

Abstract Top

The origin of the genetic code in the context of an RNA world is a major problem in the field of biophysical chemistry. In this paper, we describe how the polymerization of amino acids along RNA templates can be affected by the properties of both molecules. Considering a system without enzymes, in which the tRNAs (the translation adaptors) are not loaded selectively with amino acids, we show that an elementary translation governed by a Michaelis-Menten type of kinetics can follow different polymerization regimes: random polymerization, homopolymerization and coded polymerization. The regime under which the system is running is set by the relative concentrations of the amino acids and the kinetic constants involved. We point out that the coding regime can naturally occur under prebiotic conditions. It generates partially coded proteins through a mechanism which is remarkably robust against non-specific interactions (mismatches) between the adaptors and the RNA template. Features of the genetic code support the existence of this early translation system.

Citation: Lehmann J, Cibils M, Libchaber A (2009) Emergence of a Code in the Polymerization of Amino Acids along RNA Templates. PLoS ONE 4(6): e5773. doi:10.1371/journal.pone.0005773

Editor: Jörg Langowski, German Cancer Research Center, Germany

Received: March 10, 2009; Accepted: May 5, 2009; Published: June 3, 2009

Copyright: © 2009 Lehmann et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Funding: The authors have no support or funding to report.

Competing interests: The authors have declared that no competing interests exist.

* E-mail: jlehmann@rockefeller.edu

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