Genetic Encoding of Three Distinct Noncanonical Amino Acids Using Reprogrammed Initiator and Nonsense Codons.

ABSTRACT: We recently described an orthogonal initiator tRNA (itRNA^Ty2) that can initiate protein synthesis with noncanonical amino acids (ncAAs) in response to the UAG nonsense codon. Here, we report that a mutant of itRNA^Ty2 (itRNA^Ty2_AUA) can efficiently initiate translation in response to the UAU tyrosine codon, giving rise to proteins with an ncAA at their N-terminus. We show that, in cells expressing itRNA^Ty2_AUA, UAU can function as a dual-use codon that selectively encodes ncAAs at the initiating position and predominantly tyrosine at elongating positions. Using itRNA^Ty2_AUA, in conjunction with its cognate tyrosyl-tRNA synthetase and two mutually orthogonal pyrrolysyl-tRNA

SUBMITTER: Tharp JM 

PROVIDER: S-EPMC8336083 | biostudies-literature | 2021 Apr

REPOSITORIES: biostudies-literature