hydrolase activity, hydrolyzing O-glycosyl compounds polygalacturonase activity Catalysis of the random hydrolysis of (1->4)-alpha-D-galactosiduronic linkages in pectate and other galacturonans. EC:3.2.1.15 GO:0004650 MetaCyc:RXN-2103 endo-D-galacturonase activity endo-polygalacturonase activity endogalacturonase activity endopolygalacturonase activity molecular_function pectin depolymerase activity pectin hydrolase activity pectin polygalacturonase activity pectinase activity pectolase activity poly(1,4-alpha-D-galacturonide) glycanohydrolase activity poly-alpha-1,4-galacturonide glycanohydrolase activity