2ske | pdb_00002ske

PYRIDOXAL PHOSPHORYLASE B IN COMPLEX WITH PHOSPHITE, GLUCOSE AND INOSINE-5'-MONOPHOSPHATE

spinqualitylabelsall models 2ske, resolution 2.46Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2ske is a 1 chain structure with sequence from Oryctolagus cuniculus. This structure supersedes the now removed PDB entry 1ske. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: GLC, IMP, PLP, PO3 Activity: Phosphorylase, with EC number 2.4.1.1 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT 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 It has been established that phosphate analogues can activate glycogen phosphorylase reconstituted with pyridoxal in place of the natural cofactor pyridoxal 5'-phosphate (Change YC. McCalmont T, Graves DJ. 1983. Biochemistry 22:4987-4993). Pyridoxal phosphorylase b has been studied by kinetic, ultracentrifugation, and X-ray crystallographic experiments. In solution, the catalytically active species of pyridoxal phosphorylase b adopts a conformation that is more R-state-like than that of native phosphorylase b, but an inactive dimeric species of the enzyme can be stabilized by activator phosphite in combination with the T-state inhibitor glucose. Co-crystals of pyridoxal phosphorylase b complexed with either phosphite, phosphate, or fluorophosphate, the inhibitor glucose, and the weak activator IMP were grown in space group P4(3)2(1)2, with native-like unit cell dimensions, and the structures of the complexes have been refined to give crystallographic R factors of 18.5-19.2%, for data between 8 and 2.4 A resolution. The anions bind tightly at the catalytic site in a similar but not identical position to that occupied by the cofactor 5'-phosphate group in the native enzyme (phosphorus to phosphorus atoms distance = 1.2 A). The structural results show that the structures of the pyridoxal phosphorylase b-anion-glucose-IMP complexes are overall similar to the glucose complex of native T-state phosphorylase b. Structural comparisons suggest that the bound anions, in the position observed in the crystal, might have a structural role for effective catalysis. Activator anion binding site in pyridoxal phosphorylase b: the binding of phosphite, phosphate, and fluorophosphate in the crystal.,Oikonomakos NG, Zographos SE, Tsitsanou KE, Johnson LN, Acharya KR Protein Sci. 1996 Dec;5(12):2416-28. PMID:8976550 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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