Why these amino acids?

Date

Sep 12, 2024

Time

11:00 AM - 12:00 PM

Speaker

Klára Hlouchová

Affiliation

Charles University in Prague

Series

MPI-CBG Thursday Seminar

Language

en

Main Topic

Biologie

Host

Agnes Toth-Petroczy

Description

All extant cells known to humankind build proteins from the same 20 coded amino acids. Is this canonical alphabet a prerequisite for life to be as successful as it has been on our planet or could protein structures and functions depend on a different/smaller set of amino acids? We report structural and functional propensities of proteins and peptide libraries built from different subsets of both canonical and non-canonical amino acids, mimicking different hypothetical stages of the prebiotic-to-biological sequences. The study of origins of life implies that earlier cells functioned with a smaller alphabet, which was selected from a pool of prebiotically plausible (canonical and non-canonical) amino acids before the fixation of the Central Dogma. Our work implies that the “early” canonical amino acids that were selected from the prebiotic environment have a higher structure-forming propensity than possible alternatives. Despite lacking positively charged and aromatic residues, proteins composed from such “early” components would be prone to structure formation but also capable of interacting with organic and inorganic cofactors. On select examples, we observe that such binding can significantly assist with early protein folding as well as with catalytic and binding propensities. Our work indicates that protein folding propensity was an important factor during the earliest stages of the genetic code evolution. A reduced acidic alphabet would be sufficient to build proteins, capitalizing on interactions that are less frequent or rare in today’s biology.

Last modified: Sep 13, 2024, 7:39:48 AM