5W5R

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

5W5R の概要

• エントリーDOI: 10.2210/pdb5w5r/pdb
• 分子名称: Glucose-1-phosphate adenylyltransferase, SULFATE ION, PYRUVIC ACID, ... (4 entities in total)
• 機能のキーワード: glucose-1-phosphate adenylyltransferase, glycogen biosynthesis, starch biosynthesis, allosterism, transferase
• 由来する生物種: Rhizobium radiobacter (Agrobacterium tumefaciens)
• タンパク質・核酸の鎖数: 20
• 化学式量合計: 937919.00

構造登録者

Mascarenhas, R.N.,Hill, B.L.,Ballicora, M.A.,Liu, D. (登録日: 2017-06-15, 公開日: 2018-11-14, 最終更新日: 2023-11-15)

主引用文献

Hill, B.L.,Mascarenhas, R.,Patel, H.P.,Asencion Diez, M.D.,Wu, R.,Iglesias, A.A.,Liu, D.,Ballicora, M.A.
Structural analysis reveals a pyruvate-binding activator site in theAgrobacterium tumefaciensADP-glucose pyrophosphorylase.
J. Biol. Chem., 294:1338-1348, 2019

PubMed Abstract: 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 , 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 β-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 preactivated 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.

PubMed: 30401744
DOI: 10.1074/jbc.RA118.004246

実験手法

X-RAY DIFFRACTION (1.754 Å)