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Saturation of recognition elements blocks evolution of new tRNA identities.

ABSTRACT: Understanding the principles that led to the current complexity of the genetic code is a central question in evolution. Expansion of the genetic code required the selection of new transfer RNAs (tRNAs) with specific recognition signals that allowed them to be matured, modified, aminoacylated, and processed by the ribosome without compromising the fidelity or efficiency of protein synthesis. We show that saturation of recognition signals blocks the emergence of new tRNA identities and that the rate of nucleotide substitutions in tRNAs is higher in species with fewer tRNA genes. We propose that the growth of the genetic code stalled because a limit was reached in the number of identity elements that can be effectively used in the tRNA structure.

SUBMITTER: Saint-Leger A

PROVIDER: S-EPMC4928997 | biostudies-literature | 2016 Apr

REPOSITORIES: biostudies-literature

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Saturation of recognition elements blocks evolution of new tRNA identities.

Saint-Léger Adélaïde A Bello Carla C Dans Pablo D PD Torres Adrian Gabriel AG Novoa Eva Maria EM Novoa Eva Maria EM Camacho Noelia N Orozco Modesto M Kondrashov Fyodor A FA Ribas de Pouplana Lluís L

Science advances 20160429 4

Understanding the principles that led to the current complexity of the genetic code is a central question in evolution. Expansion of the genetic code required the selection of new transfer RNAs (tRNAs) with specific recognition signals that allowed them to be matured, modified, aminoacylated, and processed by the ribosome without compromising the fidelity or efficiency of protein synthesis. We show that saturation of recognition signals blocks the emergence of new tRNA identities and that the ra ...[more]

PMID: 27386510

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