Effect of single base insertion into anticodon loop of frameshift suppressor tRNA.

Frameshift suppressor tRNAs containing an additional nucleotide at anticodon loop were prepared and their translational activity was evaluated in an E. coli in vitro translation system. The mutated tRNA(CCCG) was chemically aminoacylated with nitrophenylalanine, and added to the in vitro translation system together with a streptavidin mRNA containing CGGG codon. Western blot analysis indicates that the mutated tRNAs can decode the four-base codon, except 32.1C and 33.1G mutants.