Streptomycin-induced, third-position misreading of the genetic code.

Streptomycin was used to increase the frequency of errors in protein synthesis in vivo. In the system under study two misreading errors were observed. Both involved the erroneous insertion of lysine at asparagine codons, because of misreading of a pyrimidine as a purine at the 3' position of the codon. Streptomycin increased the errors at the two codons AAU and AAC to the same extent, thereby maintaining the error ratio found for basal level mistranslation.