In enzymology, a deoxyuridine phosphorylase is an enzyme that catalyzes the chemical reaction

2'-deoxyuridine + phosphate ${\displaystyle \rightleftharpoons }$ uracil + 2-deoxy-alpha-D-ribose 1-phosphate

Thus, the two substrates of this enzyme are 2'-deoxyuridine and phosphate, whereas its two products are uracil and 2-deoxy-alpha-D-ribose 1-phosphate.

No enzyme is known to be specific for this reaction, hence the EC number originally assigned to this enzyme function (EC 2.4.2.23) was deleted by the IUBMB in 2013.^[1] The reaction is catalysed by EC 2.4.2.2, pyrimidine-nucleoside phosphorylase, EC 2.4.2.3, uridine phosphorylase, and EC 2.4.2.4, thymidine phosphorylase.

These enzymes belong to the family of glycosyltransferases, specifically the pentosyltransferases. They participate in pyrimidine metabolism.

• Soukhova-O'Hare GK, Roberts AM, Gozal D (2006). "Impaired control of renal sympathetic nerve activity following neonatal intermittent hypoxia in rats". Neurosci. Lett. 399 (3): 181–5. doi:10.1016/j.neulet.2006.01.054. PMID 16495004.
• Yamada EW (1964). "The effect of cortisol administration on the activities of uridine and deoxyuridine phosphorylases of normal and regenerating rat liver". Can. J. Biochem. 42: 317–325.