Structural highlights
Function[GLGA_ECOLI] Synthesizes alpha-1,4-glucan chains using ADP-glucose. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedGlycogen/starch synthase elongates glucan chains and is the key enzyme in the synthesis of glycogen in bacteria and starch in plants. Cocrystallization of Escherichia coli wild-type glycogen synthase (GS) with substrate ADPGlc and the glucan acceptor mimic HEPPSO produced a closed form of GS and suggests that domain-domain closure accompanies glycogen synthesis. Cocrystallization of the inactive GS mutant E377A with substrate ADPGlc and oligosaccharide results in the first oligosaccharide-bound glycogen synthase structure. Four bound oligosaccharides are observed, one in the interdomain cleft (G6a) and three on the N-terminal domain surface (G6b, G6c, and G6d). Extending from the center of the enzyme to the interdomain cleft opening, G6a mostly interacts with the highly conserved N-terminal domain residues lining the cleft of GS. The surface-bound oligosaccharides G6c and G6d have less interaction with enzyme and exhibit a more curled, helixlike structural arrangement. The observation that oligosaccharides bind only to the N-terminal domain of GS suggests that glycogen in vivo probably binds to only one side of the enzyme to ensure unencumbered interdomain movement, which is required for efficient, continuous glucan-chain synthesis. Oligosaccharide binding in Escherichia coli glycogen synthase.,Sheng F, Yep A, Feng L, Preiss J, Geiger JH Biochemistry. 2009 Oct 27;48(42):10089-97. PMID:19761218[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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This page was last modified 10:04, 25 December 2014.