Alpha-glucuronidase involved in the hydrolysis of xylan, a major structural heterogeneous polysaccharide found in plant biomass representing the second most abundant polysaccharide in the biosphere, after cellulose. It catalyzes the cleavage of the alpha-1,2-glycosidic bond at the non-reducing end of 4-O-methyl-D-glucuronic acid (4-O-MeGlcA) side chain of short xylooligosaccharides and releases 4-O-methylglucuronic acid. It can also hydrolyze small soluble oligosaccharides such as dobiouronic acid, aldotriouronic acid, aldotetraouronic acid, and aldopentaouronic acid. Hydrolysis of (1->2)-alpha-D-(4-O-methyl)glucuronosyl links in the main chain of hardwood xylans. Inhibited by 4-O-MeGlcA. Homodimer. Belongs to the glycosyl hydrolase 67 family.