3L01

Crystal structure of monomeric glycogen synthase from Pyrococcus abyssi

Summary for 3L01

• Entry DOI: 10.2210/pdb3l01/pdb
• Related: 1RZV 2BIS 3COP
• Related PRD ID: PRD_900010
• Descriptor: GlgA glycogen synthase, alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose, POTASSIUM ION, ... (6 entities in total)
• Functional Keywords: glycosyltransferase family, 5 udp/adp-glucose-glycogen synthase, two rossman folds, transferase
• Biological source: Pyrococcus abyssi
• Total number of polymer chains: 2
• Total formula weight: 98299.24

Authors

Diaz, A.,Martinez-Pons, C.,Fita, I.,Ferrer, J.C.,Guinovart, J.J. (deposition date: 2009-12-09, release date: 2010-12-29, Last modification date: 2024-11-20)

Primary citation

Diaz, A.,Martinez-Pons, C.,Fita, I.,Ferrer, J.C.,Guinovart, J.J.
Processivity and Subcellular Localization of Glycogen Synthase Depend on a Non-catalytic High Affinity Glycogen-binding Site.
J.Biol.Chem., 286:18505-18514, 2011

PubMed Abstract: Glycogen synthase, a central enzyme in glucose metabolism, catalyzes the successive addition of α-1,4-linked glucose residues to the non-reducing end of a growing glycogen molecule. A non-catalytic glycogen-binding site, identified by x-ray crystallography on the surface of the glycogen synthase from the archaeon Pyrococcus abyssi, has been found to be functionally conserved in the eukaryotic enzymes. The disruption of this binding site in both the archaeal and the human muscle glycogen synthases has a large impact when glycogen is the acceptor substrate. Instead, the catalytic efficiency remains essentially unchanged when small oligosaccharides are used as substrates. Mutants of the human muscle enzyme with reduced affinity for glycogen also show an altered intracellular distribution and a marked decrease in their capacity to drive glycogen accumulation in vivo. The presence of a high affinity glycogen-binding site away from the active center explains not only the long-recognized strong binding of glycogen synthase to glycogen but also the processivity and the intracellular localization of the enzyme. These observations demonstrate that the glycogen-binding site is a critical regulatory element responsible for the in vivo catalytic efficiency of GS.

PubMed: 21464127
DOI: 10.1074/jbc.M111.236109

Experimental method

X-RAY DIFFRACTION (2.6 Å)