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 alpha-(1->2)-glycosidic bond of the 4-O-methyl-D-glucuronic acid side chain of xylan and releases 4-O-methylglucuronic acid from xylan. Hydrolysis of (1->2)-alpha-D-(4-O-methyl)glucuronosyl links in the main chain of hardwood xylans. Optimum pH is 6.3 with more than 50% activity occurring between pH 5.2 and 7.9. Optimum temperature is 85 degrees Celsius. Homodimer. Belongs to the glycosyl hydrolase 67 family.