Catalyzes the synthesis of dihydrouridine, a modified base found in the D-loop of most tRNAs. Specifically modifies U47 in cytoplasmic tRNAs (By similarity). Catalyzes the synthesis of dihydrouridine in some mRNAs, thereby affecting their translation (By similarity). 5,6-dihydrouridine(47) in tRNA + NAD(+) = H(+) + NADH + uridine(47) in tRNA 5,6-dihydrouridine(47) in tRNA + NADP(+) = H(+) + NADPH + uridine(47) in tRNA a 5,6-dihydrouridine in mRNA + NAD(+) = a uridine in mRNA + H(+) + NADH a 5,6-dihydrouridine in mRNA + NADP(+) = a uridine in mRNA + H(+) + NADPH Belongs to the Dus family. Dus3 subfamily.