Subsystem: Glycogen metabolism
This subsystem's description is:
Glycogen is a storage polysaccharide in the majority of animal, fungal, bacterial, and archaebacterial species. Eukaryotes make glycogen from UDP-glucose, whereas most bacteria synthesize their storage polysaccharide from ADP-glucose. These constitute two very different pathways with distinct regulatory mechanisms and rate controlling steps. Only the latter pathway is considered in this Subsystem (Preiss, 1984).
In free-living bacteria and in mildly parasitic pathogenic bacteria, the presence of glycogen is associated with a minimum of one Glucose-1-phosphate adenylyltransferase (GAT), one glycogen synthase (GS), one glycogen phosphorylase (GP), one branching enzyme (GBr), and one debranching enzyme (GdBr), often organized in one or two operons (Ball, Morell, 2003). Aside from this core pathway of glycogen metabolism, enzymes of malto-oligosaccharide utilization are considered relevant to glycogen metabolism (they are encoded in Subsystem: Maltose_and_Maltodextrin_Utilization). Indeed, malto-oligosaccharides are bound to be produced through the action of debranching enzyme during glycogen catabolism. These malto-oligosaccharides can be processed through a combination of alpha-1,4 glucanotransferases, maltodextrin-phosphorylases, and glucosidases. In addition to this, some bacteria contain a cytosolic alpha-amylase whose function in glycogen metabolism remains unclear (Raha et al., 1992). These “accessory functions" of glycogen metabolism are not included in this Subsystem.
For more information, please check out the description and the additional notes tabs, below
|Diagram||Functional Roles||Subsystem Spreadsheet||Description||Additional Notes|
Oops! We thought there was a diagram here, but we can't find it. Sorry