3'-Deoxyuridine-5'-triphosphate (3'-dUTP) is a nucleotide analogue that inhibits DNA-dependent RNA polymerases I and II and strongly competes with UTP incorporation into RNA, with a Ki value of 2.0 μM[1].

3'-Deoxyuridine-5'-triphosphate (3'-dUTP), efficiently synthesized from cordycepin, is a potent competitive inhibitor of UTP incorporation into RNA by RNA polymerases. Its lack of effect on poly (rA) synthesis suggests its utility in dissecting template and substrate relationships within RNA synthesis, particularly in contexts involving chromatin, isolated nuclei, or permeable cells[1].