TRNA-guanine15 transglycosylase (, tRNA transglycosylase, transfer ribonucleate glycosyltransferase, tRNA guanine15 transglycosidase, TGT, transfer ribonucleic acid guanine15 transglycosylase) is an enzyme with systematic name tRNA-guanine15:7-cyano-7-carbaguanine tRNA-D-ribosyltransferase. This enzyme catalyses the following chemical reaction
Archaeal tRNAs contain the modified nucleoside archaeosine at position 15.