Alternate names of this domain include delta(2)-isopentenylpyrophosphate transferase, IPP transferase and 2-methylthio-N6-isopentyladenosine tRNA modification enzyme. It catalyzes the first step in the modification of an adenosine near the anticodon to 2-methylthio-N6-isopentyladenosine. tRNA delta(2)-isopentenylpyrophosphate transferase