Anticipating alien cells with alternative genetic codes: away from the alanine world!

Abstract

Can we make life with a different genetic amino acid repertoire? Can we expect organisms which would keep newly given genetic code associations permanently? To address these questions, we would like to analyze the existent genetic code amino acid repertoire as formed from derivatives of alanine. Derivation from alanine leads to the α-helix based biological world, the Alanine World, whereas variations in the side-chains enable tertiary folding and subsequent chemical versatility of the proteome. Proline, glycine and pyrrolysine are the rudiments in the current genetic code, indicating that the original set could be different. Furthermore, from the perspective of peptide chemistry, it shall be possible to recruit these alternative scaffolds for the construction of synthetic or alternative life. This would allow for a completely new biological world, potentially as functional and versatile as the existing one. Pursuing these options offers a strategy for a complete re-design or even de-novo creation of living organisms based on entirely different chemical make-up, with completely new set of solutions for both near and distant future biotechnologies.