Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. In enzymology, an UDP-glucuronate 4-epimerase (EC 5.1.3.6) is an enzyme that catalyzes the chemical reaction. UDP-glucuronate = UDP-D-galacturonate. Hence, this enzyme has one substrate, UDP-glucuronate, and one product, UDP-D-galacturonate. 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 4-epimerase. Other names in common use include uridine diphospho-D-galacturonic acid, UDP glucuronic epimerase, uridine diphosphoglucuronic epimerase, UDP-galacturonate 4-epimerase, uridine diphosphoglucuronate epimerase, and UDP-D-galacturonic acid 4-epimerase. This enzyme participates in starch and sucrose metabolism and nucleotide sugars metabolism.