Primordial emergence of a nucleic acid-binding protein via phase separation and statistical ornithine-to-arginine conversion.

ABSTRACT: De novo emergence demands a transition from disordered polypeptides into structured proteins with well-defined functions. However, can polypeptides confer functions of evolutionary relevance, and how might such polypeptides evolve into modern proteins? The earliest proteins present an even greater challenge, as they were likely based on abiotic, spontaneously synthesized amino acids. Here we asked whether a primordial function, such as nucleic acid binding, could emerge with ornithine, a basic amino acid that forms abiotically yet is absent in modern-day proteins. We combined ancestral sequence reconstruction and empiric deconstruction to unravel a gradual evolutionary trajectory leading from a polypeptide to a ubiquitous nucleic acid-binding protein. Intermediates along this trajectory co

SUBMITTER: Longo LM 

PROVIDER: S-EPMC7355028 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature