2pri

BINDING OF 2-DEOXY-GLUCOSE-6-PHOSPHATE TO GLYCOGEN PHOSPHORYLASE B

spinqualitylabelsall models 2pri, resolution 2.30Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2pri is a 1 chain structure with sequence from Oryctolagus cuniculus. This structure supersedes the now removed PDB entry 1pri. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: D6G, PLP Activity: Phosphorylase, with EC number 2.4.1.1 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum Function [PYGM_RABIT] Phosphorylase is an important allosteric enzyme in carbohydrate metabolism. Enzymes from different sources differ in their regulatory mechanisms and in their natural substrates. However, all known phosphorylases share catalytic and structural properties. 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 PubMed Kinetic and crystallographic studies have characterized the effect of 2-deoxy-glucose 6-phosphate on the catalytic and structural properties of glycogen phosphorylase b. Previous work on the binding of glucose 6-phosphate, a potent physiological inhibitor of the enzyme, to T state phosphorylase b in the crystal showed that the inhibitor binds at the allosteric site and induces substantial conformational changes that affect the subunit-subunit interface. The hydrogen-bond from the O-2 hydroxyl of glucose 6-phosphate to the main-chain oxygen of Val40' represents the only hydrogen bond from the sugar to the other subunit, and this interaction appears important for promoting a more "tensed" structure than native T state phosphorylase b. 2-Deoxy-glucose 6-phosphate acts competitively with both the activator AMP and the substrate glucose 1-phosphate, with Ki values of 0.53 mM and 1.23 mM, respectively. The binding of 2-deoxy-glucose 6-phosphate to T state glycogen phosphorylase b in the crystal, has been investigated and the complex phosphorylase b: 2-deoxy-glucose 6-phosphate has been refined to give a crystallographic R factor of 17.3%, for data between 8 A and 2.3 A. 2-Deoxy-glucose 6-phosphate binds at the allosteric site as the a anomer and adopts a different conformation compared to glucose 6-phosphate. The two conformations differ by 160 degrees in the torsion angle about the C-5-C-6 bond. The contacts from the phosphate group are essentially identical to those made by the phosphate of glucose 6-phosphate but the 2-deoxy glucosyl moiety binds in a quite different orientation compared to the glucosyl of glucose 6-phosphate. 2-Deoxy-glucose 6-phosphate can be accommodated in the allosteric site with very little change in the protein, while structural comparisons show that the phosphorylase b: 2-deoxy-glucose 6-phosphate complex structure is overall more similar to a glucose-like complex than to the Glc-6-P complex structure. The binding of 2-deoxy-D-glucose 6-phosphate to glycogen phosphorylase b: kinetic and crystallographic studies.,Oikonomakos NG, Zographos SE, Johnson LN, Papageorgiou AC, Acharya KR J Mol Biol. 1995 Dec 15;254(5):900-17. PMID:7500360 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Glycogen Phosphorylase

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