alpha-glucan phosphorylases. This family consists of known phosphorylases, and homologs believed to share the function of using inorganic phosphate to cleave an alpha 1,4 linkage between the terminal glucose residue and the rest of the polymer (maltodextrin, glycogen, etc.). The name of the glucose storage polymer substrate, and therefore the name of this enzyme, depends on the chain lengths and branching patterns. A number of the members of this family have been shown to operate on small maltodextrins, as may be obtained by utilization of exogenous sources. This family represents a distinct clade from the related family modeled by TIGR02093/pfam00343.

proteins similar to glycogen phosphorylase. This family is most closely related to the oligosaccharide phosphorylase domain family and other unidentified sequences. Oligosaccharide phosphorylase catalyzes the breakdown of oligosaccharides into glucose-1-phosphate units. They are important allosteric enzymes in carbohydrate metabolism.

Glucan phosphorylase [Carbohydrate transport and metabolism].

Glycogen synthase GlgA and similar proteins. This family is most closely related to the GT5 family of glycosyltransferases. Glycogen synthase (EC:2.4.1.21) catalyzes the formation and elongation of the alpha-1,4-glucose backbone using ADP-glucose, the second and key step of glycogen biosynthesis. This family includes starch synthases of plants, such as DULL1 in Zea mays and glycogen synthases of various organisms.

glycogen phosphorylase and similar proteins. This is a family of oligosaccharide phosphorylases. It includes yeast and mammalian glycogen phosphorylases, plant starch/glucan phosphorylase, as well as the maltodextrin phosphorylases of bacteria. The members of this family catalyze the breakdown of oligosaccharides into glucose-1-phosphate units. They are important allosteric enzymes in carbohydrate metabolism. The allosteric control mechanisms of yeast and mammalian members of this family are different from that of bacterial members. The members of this family belong to the GT-B structural superfamily of glycoslytransferases, which have characteristic N- and C-terminal domains each containing a typical Rossmann fold. The two domains have high structural homology despite minimal sequence homology. The large cleft that separates the two domains includes the catalytic center and permits a high degree of flexibility.

Uncharacterized protein MJ1631 OS=Methanocaldococcus jannaschii (strain ATCC 43067 / DSM 2661 / JAL-1 / JCM 10045 / NBRC 100440) OX=243232 GN=MJ1631 PE=3 SV=1

Maltodextrin phosphorylase OS=Thermococcus litoralis (strain ATCC 51850 / DSM 5473 / JCM 8560 / NS-C) OX=523849 GN=malP PE=1 SV=1

Glycogen phosphorylase OS=Aquifex aeolicus (strain VF5) OX=224324 GN=glgP PE=3 SV=1

Glycogen phosphorylase OS=Mycobacterium tuberculosis (strain CDC 1551 / Oshkosh) OX=83331 GN=glgP PE=3 SV=1

Glycogen phosphorylase OS=Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv) OX=83332 GN=glgP PE=1 SV=1