5w5r | pdb_00005w5r

Agrobacterium tumefaciens ADP-glucose pyrophosphorylase P96A mutant bound to activator pyruvate

spinqualitylabelsall models 5w5r, resolution 1.75Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 5w5r is a 20 chain structure with sequence from Agrobacterium tumefaciens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.754Å Ligands: PYR, SO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function GLGC_RHIRD Catalyzes the synthesis of ADP-glucose, a sugar donor used in elongation reactions on alpha-glucans. Publication Abstract from PubMed The pathways for biosynthesis of glycogen in bacteria and starch in plants are evolutionarily and biochemically related. They are regulated primarily by ADP-glucose pyrophosphorylase, which evolved to satisfy metabolic requirements of a particular organism. Despite the importance of these two pathways, little is known about the mechanism that controls pyrophosphorylase activity or the location of its allosteric sites. Here, we report pyruvate-bound crystal structures of ADP-glucose pyrophosphorylase from the bacterium Agrobacterium tumefaciens, identifying a previously elusive activator site for the enzyme. We found that the tetrameric enzyme binds two molecules of pyruvate in a planar conformation. Each binding site is located in a crevice between the C-terminal domains of two subunits where they stack via a distinct beta-helix region. Pyruvate interacts with the side chain of Lys-43 and with the peptide backbone of Ser-328 and Gly-329 from both subunits. These structural insights led to the design of two variants with altered regulatory properties. In one variant (K43A), the allosteric effect was absent, whereas in the other (G329D), the introduced Asp mimicked the presence of pyruvate. The latter generated an enzyme that was pre-activated and insensitive to further activation by pyruvate. Our study furnishes a deeper understanding of how glycogen biosynthesis is regulated in bacteria and the mechanism by which transgenic plants increased their starch production. These insights will facilitate rational approaches to enzyme engineering for starch production in crops of agricultural interest and will promote further study of allosteric signal transmission and molecular evolution in this important enzyme family. Structural analysis reveals a pyruvate-binding activator site in the Agrobacterium tumefaciens ADP-glucose pyrophosphorylase.,Hill BL, Mascarenhas R, Patel HP, Asencion Diez MD, Wu R, Iglesias AA, Liu D, Ballicora MA J Biol Chem. 2018 Nov 6. pii: RA118.004246. doi: 10.1074/jbc.RA118.004246. PMID:30401744 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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