tRNA isopentenyltransferases <db_xref db="EC" dbkey="2.5.1.8"/> also known as tRNA delta(2)-isopentenylpyrophosphate transferases or IPP transferases. These enzymes modify both cytoplasmic and mitochondrial tRNAs at A(37) to give isopentenyl A(37) [<cite idref="PUB00003694"/>].