Catalyzes the synthesis of dihydrouridine, a modified base, in various RNAs, such as tRNAs and mRNAs (PubMed:34798057). Modifies the uridine in position 47 (U47) in the D-loop of tRNAs (PubMed:34798057). Also able to mediate formation of dihydrouridine outside of the D-loop of tRNAs (PubMed:34798057). Catalyzes the synthesis of dihydrouridine in some mRNAs, thereby affecting their translation (PubMed:34798057). Dus3-mediated dihydrouridylation of the mRNA encoding alpha-tubulin nda2 is required for meiotic chromosome segregation (PubMed:34798057). 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 Decreased ability to complete gametogenesis. Belongs to the Dus family. Dus3 subfamily.