In enzymology, a RNA uridylyltransferase (EC 2.7.7.52) is an enzyme that catalyzes the chemical reaction

UTP + RNA_n diphosphate + RNA_n+1

Thus, the two substrates of this enzyme are UTP and RNA_n, whereas its two products are diphosphate and RNA_n+1.

This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing nucleotide groups (nucleotidyltransferases). The systematic name of this enzyme class is UTP:RNA uridylyltransferase. Other names in common use include terminal uridylyltransferase, and TUT.

As of late 2007, 8 structures have been solved for this class of enzymes, with PDB accession codes 2E5G, 2IKF, 2NOM, 2Q0C, 2Q0D, 2Q0E, 2Q0F, and 2Q0G.

• Zabel P, Dorssers L, Wernars K, Van Kammen A (June 1981). "Terminal uridylyl transferase of Vigna unguiculata: purification and characterization of an enzyme catalyzing the addition of a single UMP residue to the 3'-end of an RNA primer". Nucleic Acids Research. 9 (11): 2433–53. doi:10.1093/nar/9.11.2433. PMC 326863. PMID 6269049.