Subcellular localization of D-glucanases in Bacteroides oralis Ig4a

Three D-glucan-hydrolysing enzymes from Bacteroides oralis Ig4a have been isolated. Two of them are dextranases which hydrolyse (1----6) but not (1----3) linked alpha-D-glucans; one (EC 3.2.1.11, 1,6-alpha-D-glucan 6-glucanohydrolase) is localized in the periplasm, and the other, which is an exo-enzyme (EC 3.2.1.70, 1,6-alpha-D-glucan glucohydrolase), in the cytoplasm. The third is a mutanase (EC 3.2.1.59, 1,3-(1,3;1,4)-alpha-D-glucan 3-glucanohydrolase) that hydrolyses (1----3) but not (1----6) linked alpha-D-glucans, and is present only in the cytoplasm.