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Evolution of the genetic code: The ambiguity-reduction theory.

Marcello Barbieri1

  • 1Dipartimento di Morfologia ed Embriologia, Via Fossato di Mortara 64a, 44121 Ferrara, Italy.

Bio Systems
|September 10, 2019
PubMed
Summary

The genetic code

Area of Science:

  • Molecular Biology
  • Genetics
  • Biochemistry

Background:

  • Experimental evidence indicates the genetic code operates on arbitrary rules, not deterministic chemical affinities.
  • This contradicts the stereochemical theory, which posits chemistry dictates codon-amino acid relationships.

Purpose of the Study:

  • To address the challenge of how arbitrary genetic code rules could arise in nature.
  • To propose a generalized mechanism for the evolution of the genetic code.

Main Methods:

  • Review and extension of the ribosome-oriented model.
  • Development of the ambiguity-reduction theory.

Main Results:

  • The initial genetic code was likely ambiguous.
Keywords:
AdaptorsBiological specificityCode ambiguityCode arbitrarinessError minimizationGenetic codeRibosomesStatistical proteinsStereochemical theory

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  • A mechanism of ambiguity reduction, involving ribosomal proteins and other factors, led to the current, unambiguous code.
  • The proposed ambiguity-reduction theory offers a more comprehensive explanation.

    • Conclusions:

    • The genetic code evolved from an ambiguous state through a process of ambiguity reduction.
    • This evolutionary pathway explains the arbitrary nature of the modern genetic code.
    • The ambiguity-reduction theory provides a framework for understanding this crucial biological process.