1AHP

OLIGOSACCHARIDE SUBSTRATE BINDING IN ESCHERICHIA COLI MALTODEXTRIN PHSPHORYLASE

Summary for 1AHP

• Entry DOI: 10.2210/pdb1ahp/pdb
• Related PRD ID: PRD_900001
• Descriptor: E.COLI MALTODEXTRIN PHOSPHORYLASE, alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose, SULFATE ION, ... (5 entities in total)
• Functional Keywords: ecoli, phosphorylase, oligosaccharide, induced-fit, substrate, maltodextrin, stacking
• Biological source: Escherichia coli
• Total number of polymer chains: 2
• Total formula weight: 182285.21

Authors

O'Reilly, M.,Watson, K.A.,Schinzel, R.,Palm, D.,Johnson, L.N. (deposition date: 1997-04-10, release date: 1997-10-15, Last modification date: 2024-04-03)

Primary citation

O'Reilly, M.,Watson, K.A.,Schinzel, R.,Palm, D.,Johnson, L.N.
Oligosaccharide substrate binding in Escherichia coli maltodextrin phosphorylase.
Nat.Struct.Biol., 4:405-412, 1997

PubMed Abstract: The crystal structure of E. coli maltodextrin phosphorylase co-crystallized with an oligosaccharide has been solved at 3.0 A resolution, providing the first structure of an oligosaccharide bound at the catalytic site of an alpha-glucan phosphorylase. An induced fit mechanism brings together two domains across the catalytic site tunnel. A stacking interaction between the glucosyl residue and the aromatic group of a tyrosine residue at a sub-site remote (8 A) from the catalytic site provides a key element in substrate recognition; mutation of this residue to Ala decreases the Kcat/Km by 10(4). Extrapolation of the results to substrate binding across the site of attack by phosphorolysis indicates a likely alteration in the glycosidic torsion angles from their preferred values, an alteration that appears to be important for the catalytic mechanism.

PubMed: 9145112
DOI: 10.1038/nsb0597-405

Experimental method

X-RAY DIFFRACTION (3 Å)