Utilização de aminoácidos nas proteínas primitivas e a origem do código genético

Abstract

Understand how did the genetic code and how proteins synthesized by it is of extreme importance for understanding the evolution of the first cell and consequently the first organism, the LUCA. As theories about the evolution of the genetic code mainly argue about the first links between as molecules of the tRNA, and the amino acids. Among such theories are one of Francis Crick suggesting that the code would have been frozen, Carl Woese who propose a esterioquímica theory, the model minimization of errors, the model of the Wong on a coevolucão, the model of the genetic code of the Hartman, and the Romeo Guimarães autoreferente model. In this work we what to were the first amino acids into the genetic code and compose as primitive proteins, based on statistical analysis (means and variances) of amino acids of the protein translated from tRNA ancestry withdrawn FARIAS et al (2016) and the genomes of life domains (Bacteria, Archaea and Eukarya), removed from the database program (use of CODON online www.kasusa.or.jp/CODON). The journey of the results, we suggest that the high average of the amino acid arginine does not prebiotics in proteins derived from the translation of tRNA ancestry should become a high average of serine (prebiotics) too high in protein derived from translation of tRNA ancestry . And that a high average of the amino acid lysine (not prebiotic) in the fields of life (Bacteria, Archaea and Eukarya) is a mechanism for minimizing error where a mutation in the second base of the codon of arginine results in lysine. As high averages for amino acids, aliphatic type R apolar strengthens the esterioquímico model. The high levels of alanine in the realms of life must become as replacements that have occurred in the evolutionary process of the amino acid glycine (mediumhigh in protein derived from the translation of the tRNA) by alanine. The amino acids that higher rates of variance was were of great importance for the entry of hydrophobic amino acids and the phase 1 in the genetic code.