In enzymology, an UDP-glucuronate 5'-epimerase (EC 5.1.3.12) is an enzyme that catalyzes the chemical reaction

UDP-glucuronate UDP-L-iduronate

Hence, this enzyme has one substrate, UDP-glucuronate, and one product, UDP-L-iduronate.

This enzyme belongs to the family of isomerases, specifically those racemases and epimerases acting on carbohydrates and derivatives. The systematic name of this enzyme class is UDP-glucuronate 5'-epimerase. Other names in common use include uridine diphosphoglucuronate 5'-epimerase, UDP-glucuronic acid 5'-epimerase, and C-5-uronosyl epimerase. This enzyme participates in nucleotide sugars metabolism. It employs one cofactor, NAD+.

• Jacobson B, Davidson EA (March 1962). "Biosynthesis of uronic acids by skin enzymes. I. Uridine diphosphate-D-glucuronic acid-5-epimerase". The Journal of Biological Chemistry. 237 (3): 638–42. doi:10.1016/S0021-9258(18)60347-3. PMID 14450717.