During the 1960s it was established that the modified nucleosides present in tRNA and rRNA are synthesized after the primary transcript is made. To obtain tRNA lacking only one modified nucleoside, a mutant defective in the synthesis of one modified nucleoside is required. This paper inspired the author to use a transposon to obtain mutants defective in tRNA methylation. Using such a method, the author discovered the metabolic link between the synthesis of aromatic amino acids and the synthesis of uridine-5-oxyacetic acid (cmo5U) and its methyl ester (mcmo5U). Provided that the tRNA(mcmo5U34)methyltransferase is a multimeric complex, poor translation termination mediated by a defective RF2 would extend the CmoA peptide, making it unable to form a potential complex required for the tRNA(mcmo5U34)methyltransferase activity. The sufC10 as well as sufC13 and sufC14 mutants have suppressor specificity similar to that induced by sufA6 and sufB2. It later emerged that these mutants each contain mutations in two genes: sufX and sufY. The sufC10 mutants contain the sufX201 and sufY204 mutations; sufC13 mutants, the sufX202 and sufY205 mutations; and the sufC14 mutant, the sufX203 and sufY206 mutations. The frameshift tRNA suppressors isolated more than 30 years ago in the laboratory of John Roth have clearly been important tools to study how the ribosome maintains the reading frame. Recent analyses using this collection of frameshift suppressor mutants have revealed new facts of the operational mechanism behind this important and conserved feature of translation.