Early Selection of the Amino Acid Alphabet Was Adaptively Shaped by Biophysical Constraints of Foldability.

ABSTRACT: Whereas modern proteins rely on a quasi-universal repertoire of 20 canonical amino acids (AAs), numerous lines of evidence suggest that ancient proteins relied on a limited alphabet of 10 "early" AAs and that the 10 "late" AAs were products of biosynthetic pathways. However, many nonproteinogenic AAs were also prebiotically available, which begs two fundamental questions: Why do we have the current modern amino acid alphabet and would proteins be able to fold into globular structures as well if different amino acids comprised the genetic code? Here, we experimentally evaluate the solubility and secondary structure propensities of several prebiotically relevant amino acids in the context of synthetic combinatorial 25-mer peptide libraries. The most prebiotically abundant linear aliphatic an

SUBMITTER: Makarov M 

PROVIDER: S-EPMC10017022 | biostudies-literature | 2023 Mar

REPOSITORIES: biostudies-literature