Evolução da síntese da proteína a partir de um mundo de RNA

quinta-feira, julho 08, 2010

Evolution of Protein Synthesis from an RNA World

Harry F. Noller

-Author Affiliations

Center for Molecular Biology of RNA and Department of Molecular, Cell, and Developmental Biology, Sinsheimer Laboratories, University of California at Santa Cruz, Santa Cruz, California 95064
Correspondence:harry@nuvolari.ucsc.edu

General mechanism of eukaryotic protein synthesis

SUMMARY

Because of the molecular complexity of the ribosome and protein synthesis, it is a challenge to imagine how translation could have evolved from a primitive RNA World. Two specific suggestions are made here to help to address this, involving separate evolution of the peptidyl transferase and decoding functions. First, it is proposed that translation originally arose not to synthesize functional proteins, but to provide simple (perhaps random) peptides that bound to RNA, increasing its available structure space, and therefore its functional capabilities. Second, it is proposed that the decoding site of the ribosome evolved from a mechanism for duplication of RNA. This process involved homodimeric “duplicator RNAs,” resembling the anticodon arms of tRNAs, which directed ligation of trinucleotides in response to an RNA template.

Copyright © 2010 Cold Spring Harbor Laboratory Press; all rights reserved

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PERGUNTA INDISCRETA DESTE BLOGGER:

A evolução é um processo de n mecanismos, sendo a seleção natural o mais importante desde o tempo de Darwin (ele a chamava de minha teoria). Aqui, os autores propõem a evolução como tendo ocorrido duas vezes e separadamente. Como ocorreu a evolução destes elementos químicos e suas complexas interações? 

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