This family includes human glycogen branching enzyme AGL []and yeast Gdb1 []. This enzyme contains a number of distinct catalytic activities. In Saccharomyces cerevisiae, Gdb1 is a multifunctional enzyme that acts as 1,4-alpha-D-glucan:1,4-alpha-D-glucan 4-alpha-D-glycosyltransferase and amylo-1,6-glucosidase in glycogen degradation [].
This is a glucanotransferase catalytic domain of the glycogen debranching enzyme AGL. AGL is a multifunctional enzyme acting as 1,4-alpha-D-glucan:1,4-alpha-D-glucan 4-alpha-D-glycosyltransferase and amylo-1,6-glucosidase in glycogen degradation []. This glucanotransferase domain is predicted to have a structure of a 8 stranded alpha/beta barrel (TIM barrel) where strands are interrupted by long loops and additional mini-domains.
This entry represents the C-terminal domain of the glycogen debranching enzyme AGL. AGL is a multifunctional enzyme acting as 1,4-alpha-D-glucan:1,4-alpha-D-glucan 4-alpha-D-glycosyltransferase and amylo-1,6-glucosidase in glycogen degradation []. This is a glucosidase domain. Mutations in this region disrupt the glucosidase activity [].
This entry represents the central domain of the glycogen debranching enzyme AGL. AGL is a multifunctional enzyme acting as 1,4-alpha-D-glucan:1,4-alpha-D-glucan 4-alpha-D-glycosyltransferase and amylo-1,6-glucosidase in glycogen degradation []. This central domain follows the glucanotransferase domain and precedes the glucosidase domain. By analogy with baterial GDEs (glycogen debranching enzymes), this domain may be involved in substrate binding either for the N-terminal glucanotransferase and/or the C-terminal glucosidase (or both).