Figure 3.

G1. (A) Thermolabile tRNA_CUA. The tRNA_CUA is functional only at the permissive temperature. (B) Inducible transcription of tRNA_CUA. The tRNA_CUA gene is expressed only in the presence of an inducer. (C) Inducible aaRS. The aaRS is produced only in the presence of an inducer. The aaRS/tRNA_CUA pair must be orthogonal to those of a host organism. (D) Introduction of the tRNA_CUA gene. The tRNA_CUA gene can be introduced using either a physical method such as electroporation or a genetic method such as crossing between a tRNA_CUA gene carrying a strain and a target gene carrying a strain. Open arrows indicate the promoters.