glycogen/starch/alpha-glucan phosphorylases. This family consists of phosphorylases. Members use phosphate to break alpha 1,4 linkages between pairs of glucose residues at the end of long glucose polymers, releasing alpha-D-glucose 1-phosphate. The nomenclature convention is to preface the name according to the natural substrate, as in glycogen phosphorylase, starch phosphorylase, maltodextrin phosphorylase, etc. Name differences among these substrates reflect differences in patterns of branching with alpha 1,6 linkages. Members include allosterically regulated and unregulated forms. A related family, TIGR02094, contains examples known to act well on particularly small alpha 1,4 glucans, as may be found after import from exogenous sources. [Energy metabolism, Biosynthesis and degradation of polysaccharides]

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.

Carbohydrate phosphorylase. The members of this family catalyze the formation of glucose 1-phosphate from one of the following polyglucoses; glycogen, starch, glucan or maltodextrin.

maltodextrin phosphorylase; Provisional

glycogen phosphorylase; Provisional

Crystalstructure of human brain glycogen phosphorylase [Homo sapiens],5IKP_A Crystal structure of human brain glycogen phosphorylase bound to AMP [Homo sapiens]

GlycogenPhosphorylase in complex with CK898 [Oryctolagus cuniculus]

ChainA, Glycogen phosphorylase, muscle form [Oryctolagus cuniculus]

Rabbitmuscle glycogen phosphorylase b in complex with N- cyclohexancarbonyl-N-beta-D-glucopyranosyl urea determined at 1.83 A resolution [Oryctolagus cuniculus]

Structureof rabbit muscle glycogen phosphorylase in complex with ligand [Oryctolagus cuniculus]

Glycogen phosphorylase, brain form OS=Bos taurus OX=9913 GN=PYGB PE=2 SV=3

Glycogen phosphorylase, muscle form OS=Ovis aries OX=9940 GN=PYGM PE=2 SV=3

Glycogen phosphorylase, muscle form OS=Bos taurus OX=9913 GN=PYGM PE=1 SV=3

Glycogen phosphorylase, brain form OS=Ovis aries OX=9940 GN=PYGB PE=2 SV=3

Glycogen phosphorylase, brain form OS=Homo sapiens OX=9606 GN=PYGB PE=1 SV=5