A Designed Phenylalanyl-tRNA Synthetase Variant Allows Efficient in Vivo Incorporation of Aryl Ketone Functionality into Proteins

Abstract

Incorporation of non-natural amino acids into proteins in vivo expands the scope of protein synthesis and design. p-Acetylphenylalanine was incorporated into recombinant dihydrofolate reductase (DHFR) in Escherichia coli via a computationally designed mutant form of the phenylalanyl-tRNA synthetase of the host. DHFR outfitted with ketone functionality can be chemoselectively ligated with hydrazide reagents under mild conditions.