Co-Expression of Yeast Amber Suppressor tRNA^Tyr and Tyrosyl-tRNA Synthetase in Escherichia coli: Possibility to Expand the Genetic Code

Abstract

An efficient system was developed for the co-expression of a yeast tRNA^Tyr/tyrosyl-tRNA synthetase (TyrRS) pair in Escherichia coli.. Analysis of suppression patterns using several sets of E. coli and λ phage mutants indicated that the expressed yeast suppressor tRNA^Tyr was aminoacylated only with tyrosine by its cognate yeast TyrRS and not by E. coli TyrRS or other aminoacyl-tRNA synthetases. This extra tRNA/TyrRS pair is expected to be a key bridgehead for developing an in vivo system for the site-directed incorporation of unnatural amino acids into proteins.