Gellan tetrasaccharide unsaturated glucuronyl hydrolase (, UGL, unsaturated glucuronyl hydrolase) is an enzyme with systematic name beta-D-4-deoxy-Delta4-GlcAp-(1->4)-beta-D-Glcp-(1->4)-alpha-L-Rhap-(1->3)-beta-D-Glcp beta-D-4-deoxy-Delta4-GlcAp hydrolase. This enzyme catalyses the following chemical reaction
The enzyme releases 4-deoxy-4(5)-unsaturated D-glucuronic acid from oligosaccharides produced by polysaccharide lyases.