Nucleotide-amino acid interactions and their relation to the genetic code

Area of Science:

• Biochemistry and Molecular Evolution
• Origin of Life Studies
• Chemical Biology

Background:

• The genetic code links nucleotide sequences to amino acid sequences in proteins.
• Understanding the prebiotic mechanisms that led to the genetic code is a fundamental question in the origin of life.
• Previous hypotheses have explored various chemical and physical interactions between nucleotides and amino acids.

Purpose of the Study:

• To investigate the chemical basis for the association between nucleotides and amino acids.
• To explore the role of these interactions in the emergence of the genetic code.
• To propose a model for early information storage relevant to the nucleotide-amino acid connection.

Main Methods:

• Measurement of apparent dissociation constants for complexes of adenosine monophosphate (AMP) with methyl esters of various amino acids in aqueous solution.
• Correlation analysis of these dissociation constants with established features of the genetic code.
• Correlation analysis with the observed frequencies of amino acid residues in known protein sequences.

Main Results:

• Significant correlations were found between AMP-amino acid complex stability (dissociation constants) and both genetic code patterns and amino acid frequencies in proteins.
• These correlations suggest that specific chemical affinities between nucleotides and amino acids played a role in early chemical evolution.
• The findings support the hypothesis that selective chemical interactions were a driving force in the origin of the genetic code.

Conclusions:

• Chemically selective nucleotide-amino acid interactions were likely instrumental in the prebiotic processes leading to the genetic code.
• A novel information storage device is proposed, based on these observed correlations.
• This proposed device involves simultaneous polymerization processes leading to both polynucleotides and polypeptides, reflecting early molecular systems.