Catalyzes the depolymerization of both polygalacturonate and pectins of methyl esterification degree from 22 to 89%, with an endo mode of action. In contrast to the majority of pectate lyases, displays high activity on highly methylated pectins (By similarity). Eliminative cleavage of (1->4)-alpha-D-galacturonan to give oligosaccharides with 4-deoxy-alpha-D-galact-4-enuronosyl groups at their non-reducing ends. Eliminative cleavage of (1->4)-alpha-D-galacturonan methyl ester to give oligosaccharides with 4-deoxy-6-O-methyl-alpha-D-galact-4-enuronosyl groups at their non-reducing ends. Binds 1 Ca(2+) ion per subunit. Glycan metabolism; pectin degradation; 2-dehydro-3-deoxy-D-gluconate from pectin: step 2/5. Belongs to the polysaccharide lyase 3 family.