The noncanonical amino acid p-azidomethyl-l-phenylalanine can be genetically incorporated into proteins in bacteria, and has been used both as a spectroscopic probe and for the selective modification of proteins by alkynes using click chemistry. Here we report identification of Escherichia coli tyrosyl tRNA synthetase mutants that allow incorporation of p-azidomethyl-l-phenylalanine into proteins in yeast. When expressed together with the cognate E. coli tRNA_CUA^Tyr, the new mutant tyrosyl tRNA synthetases directed robust incorporation of p-azidomethyl-l-phenylalanine into a model protein, human superoxide dismutase, in response to the UAG amber nonsense codon. Mass spectrometry analysis of purified superoxide dismutase proteins confirmed the efficient site-specific incorporation of p-azidomethyl-l-phenylalanine. This work provides an additional tool for the selective modification of proteins in eukaryotic cells.

非规范氨基酸对-叠氮基甲基-1-苯基丙氨酸可以遗传地掺入细菌的蛋白质中，并且既用作光谱探针，也用于炔烃使用点击化学对蛋白质的选择性修饰。在这里，我们报告的鉴定大肠杆菌酪氨酰tRNA合成酶的突变体，允许掺入p -azidomethyl-升苯丙氨酸到酵母蛋白。当与同源一起表达大肠杆菌的tRNA _CUA^的Tyr，新突变体酪氨酰tRNA合成酶涉及的健壮掺入p -azidomethyl-升-将苯丙氨酸转化为模型蛋白，人类超氧化物歧化酶，以响应UAG琥珀色无义密码子。纯化的超氧化物歧化酶蛋白的质谱分析证实了对-叠氮甲基-1-苯丙氨酸的有效位点特异性掺入。这项工作为真核细胞中蛋白质的选择性修饰提供了额外的工具。