In enzymology, a 2'-phosphotransferase () is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are 2'-phospho-[ligated tRNA] and NAD<sup>+</sup>, whereas its 4 products are mature tRNA, ADP-ribose 1,2-phosphate, nicotinamide, and H<sub>2</sub>O.
This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing groups (phosphotransferases) with an alcohol group as acceptor. The systematic name of this enzyme class is 2'-phospho-[ligated tRNA]:NAD+ phosphotransferase. Other names in common use include yeast 2'-phosphotransferase, Tpt1, Tpt1p, and 2'-phospho-tRNA:NAD+ phosphotransferase.