tRNA–guanine transglycosylase (None)

tRNA–guanine transglycosylase (TGT) is a key RNA-modifying enzyme found across all domains of life—bacteria, archaea, and eukaryotes. Its primary function is to catalyze the exchange of guanine for modified bases at specific positions in tRNAs, a crucial step in posttranscriptional modification that affects translation fidelity and efficiency. In eukaryotes and eubacteria, TGT introduces queuine into the anticodon loop (position 34) of certain tRNAs (those for Asp, Asn, His, Tyr). In archaea, TGT incorporates archaeosine into the D-loop of appropriate tRNAs. These modifications are essential for proper decoding during protein synthesis and can influence cellular responses to stress or disease states.

Catalyzes the exchange of guanine for modified bases at specific positions in tRNAs.