tRNA isopentenyltransferases EC: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) [1].
Boguta M, Hunter LA, Shen WC, Gillman EC, Martin NC, Hopper AK.
Subcellular locations of MOD5 proteins: mapping of sequences sufficient for targeting to mitochondria and demonstration that mitochondrial and nuclear isoforms commingle in the cytosol.
Mol. Cell. Biol. 14 2298-306 1994
[PubMed: 8139535] http://mcb.asm.org/cgi/content/abstract/14/4/2298