Galactosidase that is able to hydrolyze the alpha-1,6 disaccharide melibiose and the synthetic p-nitrophenyl alpha-galactoside substrate (pNP-Gal), with retention of the anomeric configuration. Does not hydrolyze DNP-Glc or pNP-Glc. Hydrolysis of terminal, non-reducing alpha-D-galactose residues in alpha-D-galactosides, including galactose oligosaccharides, galactomannans and galactolipids. Binds 1 Ca(2+) ion per subunit. Inhibited by EDTA in vitro. kcat is 244 sec(-1) with p-nitrophenyl alpha-galactoside as substrate (at pH 6.0 and 37 degrees Celsius). Optimum pH is 8.0 with p-nitrophenyl alpha-galactoside as substrate. Monomer. Belongs to the glycosyl hydrolase 97 family.