This gene encodes a cytoplasmic protein that catalyzes the conversion of uridine residues to dihydrouridine in the D-loop of tRNA. The resulting modified bases confer enhanced regional flexibility to tRNA. The encoded protein may increase the rate of translation by inhibiting an interferon-induced protein kinase. This gene has been implicated in pulmonary carcinogenesis. Alternatively spliced transcript variants have been described for this gene.