Hu et al. (2003) identified TRPT1, the homolog of S. cerevisiae tRNA phosphotransferase-1 (TPT1). In yeast, TPT1 catalyzes the removal of the 2-prime-phosphate from ligated tRNA during pre-tRNA splicing and maturation. The deduced 253-amino acid human protein has a predicted molecular mass of 27.8 kD and contains a DUF60/KptA domain. It shares 83% and 40% sequence identity with the mouse and S. cerevisiae homologs, respectively. Northern blot analysis detected a 1.0-kb transcript with highest expression in skeletal muscle followed by heart, intermediate expression in kidney and liver, low expression in thymus and placenta, barely detectable expression in brain and colon, and no expression in spleen, small intestine, lung, and peripheral blood leukocytes.