3CX4

Crystal Structure of E.coli GS mutant E377A in complex with ADP and oligosaccharides

Summary for 3CX4

• Entry DOI: 10.2210/pdb3cx4/pdb
• Related: 3COP
• Related PRD ID: PRD_900001 PRD_900009 PRD_900030
• Descriptor: Glycogen synthase, alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose, alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose, ... (10 entities in total)
• Functional Keywords: glycosyl-transferase, gt-b fold, rossmann fold, closed-form, adp and oligosaccharide binding, glycogen biosynthesis, glycosyltransferase, transferase
• Biological source: Escherichia coli
• Total number of polymer chains: 1
• Total formula weight: 59800.16

Authors

Sheng, F.,Geiger, J.H. (deposition date: 2008-04-23, release date: 2009-04-28, Last modification date: 2023-08-30)

Primary citation

Sheng, F.,Yep, A.,Feng, L.,Preiss, J.,Geiger, J.H.
Oligosaccharide binding in Escherichia coli glycogen synthase.
Biochemistry, 48:10089-10097, 2009

PubMed Abstract: Glycogen/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.

PubMed: 19761218
DOI: 10.1021/bi900916t

Experimental method

X-RAY DIFFRACTION (2.29 Å)